# Simple Numerology API

> Simple Numerology API is a numerology REST API: one POST with a name and a date of birth returns a complete Pythagorean numerology chart as 47 JSON fields (life path, destiny, soul urge, personality, karmic lessons and debts, planes of expression, pinnacles, challenges and life cycles). It also computes personal cycles and compatibility. The calculation is deterministic and follows one documented, frozen set of conventions, and no names are stored.

- Base URL: https://simplenumerologyapi.com. Authenticate with an `X-API-Key: nk_live_…` header; keys are free from https://simplenumerologyapi.com/account.
- Endpoints: `POST /v1/charts/pythagorean` (one chart), `POST /v1/charts/batch` (up to 100 charts), `POST /v1/cycles` (personal and universal year, month, day), `POST /v1/compatibility` (two people, a 0–100 score), `GET /v1/account` (plan and remaining quota).
- Plans: Free, 100 requests a month with no card; Starter, 10,000 requests a month for $9; Pro, 500,000 requests a month for $49.
- Master numbers 11, 22 and 33 are kept, so a numeric field can hold two digits.
- An MCP server for AI assistants runs at https://simplenumerologyapi.com/mcp (Streamable HTTP; OAuth or an API key).

## Docs

- [API reference](https://simplenumerologyapi.com/docs.md): every endpoint, field, error code, quota and calculation convention
- [OpenAPI 3.1 document](https://simplenumerologyapi.com/openapi.json): the machine-readable contract, for generating a client
- [Postman collection](https://simplenumerologyapi.com/postman_collection.json)
- [Changelog](https://simplenumerologyapi.com/changelog)

## Guides

- [How to choose the best numerology API](https://simplenumerologyapi.com/best-numerology-api.md): How to choose the best numerology API for your app. A 10-point checklist covering conventions, master numbers, determinism, privacy, errors, quotas, OpenAPI, a free tier, real names and batch requests.
- [Bulk numerology charts in one request](https://simplenumerologyapi.com/bulk-numerology-api.md): A batch numerology API. Compute up to 100 numerology charts in one request, from a CSV, a user table or a backfill, with the same 47 fields per chart as JSON.
- [The cheapest numerology API at volume](https://simplenumerologyapi.com/cheapest-numerology-api.md): A low-cost numerology API. 10,000 requests for $9 a month or 500,000 for $49, under $0.10 per 1,000 charts, with a free plan and overage at $0.10 per 1,000.
- [A free numerology API](https://simplenumerologyapi.com/free-numerology-api.md): A free numerology API with 100 requests a month, every endpoint and no credit card. Paid plans start at $9 for 10,000 requests.
- [Life Path Number API](https://simplenumerologyapi.com/life-path-number-api.md): A life path number API that gets the master numbers right. Send a birthdate, get the life path number as JSON, plus pinnacles, challenges and life cycles.
- [Name Numerology API](https://simplenumerologyapi.com/name-numerology-api.md): A name numerology API. Send a full name and get destiny (expression), soul urge, personality and 10 more name numbers as JSON, with accents and compound surnames handled.
- [The best numerology API, compared](https://simplenumerologyapi.com/numerology-api-comparison.md): Numerology APIs compared on price, free tier, calculations and integration. Why Simple Numerology API is the simplest, easiest and most accurate numerology API, next to RoxyAPI, Divine API, The Numerology API and AstrologyAPI.
- [A numerology API for astrology apps](https://simplenumerologyapi.com/numerology-api-for-astrology-apps.md): Add numerology to an astrology or horoscope app with a numerology API. Life path, daily personal numbers and compatibility as JSON, next to the birth data you already collect.
- [A numerology API for mobile apps](https://simplenumerologyapi.com/numerology-api-for-mobile-apps.md): Build an iOS or Android numerology app on a numerology API. Life path, daily personal numbers and compatibility as JSON, with the right way to keep your API key off the device.
- [Numerology API for JavaScript and Node.js](https://simplenumerologyapi.com/numerology-api-javascript.md): Add numerology charts to a Node.js, Next.js, Deno or Bun app with one fetch call. A free numerology REST API with JSON responses and 47 fields per chart.
- [Numerology API for PHP](https://simplenumerologyapi.com/numerology-api-php.md): Calculate life path, destiny and soul urge numbers in PHP with a numerology REST API. Working examples with cURL and Guzzle, for Laravel, Symfony or plain PHP.
- [Numerology API for Python](https://simplenumerologyapi.com/numerology-api-python.md): Calculate life path, destiny and soul urge numbers in Python. A free numerology REST API with JSON responses and 47 fields per chart, called with plain requests.
- [A numerology calculator for WordPress](https://simplenumerologyapi.com/numerology-api-wordpress.md): Add a numerology calculator to a WordPress site with a numerology API and a small shortcode. Life path, destiny and soul urge numbers, with your key kept on the server.
- [Numerology Calculator API](https://simplenumerologyapi.com/numerology-calculator-api.md): A numerology API that works as a calculator. Send a name and a birthdate, get life path, destiny, soul urge, karmic debts and 40+ more numbers as JSON.
- [Numerology Compatibility API](https://simplenumerologyapi.com/numerology-compatibility-api.md): A numerology compatibility API for dating, astrology and wellness apps. Send two people, get a 0–100 score, a rating and the pairing behind each core number as JSON.
- [A numerology MCP server for AI assistants](https://simplenumerologyapi.com/numerology-mcp-server.md): A numerology MCP server so Claude and other AI assistants compute real charts instead of guessing. Life path, cycles and compatibility as tools, backed by the numerology API.
- [A numerology SDK for any language](https://simplenumerologyapi.com/numerology-sdk.md): Generate a typed numerology API SDK in Go, Java, C#, PHP, Ruby, Swift, TypeScript or Python from the OpenAPI 3.1 spec, or try every endpoint with the Postman collection.
- [Personal Year Number API](https://simplenumerologyapi.com/personal-year-number-api.md): A numerology forecast API. Send a birthdate and get the personal year, month and day numbers, the universal numbers and the years ahead as JSON. Built for daily horoscope screens.
- [Pythagorean vs Chaldean numerology](https://simplenumerologyapi.com/pythagorean-vs-chaldean-numerology.md): Pythagorean vs Chaldean numerology side by side. Both letter charts, a worked name example, what each system counts and which one to use in an app.
- [The simplest numerology REST JSON API](https://simplenumerologyapi.com/simple-numerology-rest-api.md): The simplest numerology REST API. One POST with a name and a birthdate returns a full numerology chart as JSON. One header, no SDK required, OpenAPI 3.1 spec included.

## Free calculators

All 33 are listed at https://simplenumerologyapi.com/numerology-calculators. They need no key and use the API's engine.

- [Active number calculator](https://simplenumerologyapi.com/active-number-calculator.md): Free Active number calculator. Enter your first name to get its numerology Active number, which describes your everyday self, and its Growth number.
- [Attitude number calculator](https://simplenumerologyapi.com/attitude-number-calculator.md): Free Attitude number calculator. Enter your date of birth to get your numerology Attitude number, the birth month plus the birth day, and your Life Path.
- [Balance number calculator](https://simplenumerologyapi.com/balance-number-calculator.md): Free Balance number calculator. Enter your full birth name to get the numerology Balance number from your initials, which describes how you handle difficult moments.
- [Birthday number calculator](https://simplenumerologyapi.com/birthday-number-calculator.md): Free Birthday number calculator. Enter your date of birth to get your numerology Birthday number, with master numbers 11 and 22 kept, and your Life Path.
- [Bridge numbers calculator](https://simplenumerologyapi.com/bridge-numbers-calculator.md): Free Bridge numbers calculator. Enter your full name and date of birth to get the numerology bridges between your Life Path and Expression, and your Soul Urge and Personality.
- [Business name numerology calculator](https://simplenumerologyapi.com/business-name-numerology-calculator.md): Free business name numerology calculator. Enter a company or brand name to get its Expression number, plus the Soul Urge of its vowels and the Personality of its consonants.
- [Chaldean numerology calculator](https://simplenumerologyapi.com/chaldean-numerology-calculator.md): Free Chaldean numerology calculator. Enter the name you go by to get its Chaldean name number and compound number, with the Pythagorean number for comparison.
- [Challenge numbers calculator](https://simplenumerologyapi.com/challenge-numbers-calculator.md): Free Challenge numbers calculator. Enter your date of birth to get your four numerology Challenges, the ages each covers, your main Challenge and the one you face now.
- [Cornerstone and Capstone calculator](https://simplenumerologyapi.com/cornerstone-capstone-calculator.md): Free Cornerstone and Capstone calculator. Enter your first name to get the numerology numbers of its first letter, its last letter and its first vowel.
- [Expression number calculator](https://simplenumerologyapi.com/expression-number-calculator.md): Free Expression number calculator, also called the Destiny number. Enter your full birth name to get your Expression number, plus your Soul Urge and Personality numbers.
- [Heritage number calculator](https://simplenumerologyapi.com/heritage-number-calculator.md): Free Heritage number calculator. Enter your full birth name to get the numerology Heritage number of your family name, and the Active number of your first name.
- [Hidden Passion number calculator](https://simplenumerologyapi.com/hidden-passion-number-calculator.md): Free Hidden Passion number calculator. Enter your full birth name to find the number that appears most often in its letters, your numerology Hidden Passion.
- [House number numerology calculator](https://simplenumerologyapi.com/house-number-numerology-calculator.md): Free house number numerology calculator. Enter a house or apartment number, letters included, to get its numerology number and what kind of home it makes.
- [Points of Intensity calculator](https://simplenumerologyapi.com/intensity-points-calculator.md): Free Points of Intensity calculator. Enter your full birth name to find the numbers that appear more often than average in its letters, and the count of each from 1 to 9.
- [Karmic debt calculator](https://simplenumerologyapi.com/karmic-debt-calculator.md): Free karmic debt calculator. Enter your full birth name and date of birth to find any karmic debt numbers, 13, 14, 16 or 19, in your numerology chart, and your karmic lessons.
- [Karmic lesson calculator](https://simplenumerologyapi.com/karmic-lesson-calculator.md): Free karmic lesson calculator. Enter your full birth name to find the numbers from 1 to 9 missing from its letters, your numerology karmic lessons, and your Subconscious Self number.
- [Life Cycle numbers calculator](https://simplenumerologyapi.com/life-cycle-numbers-calculator.md): Free Life Cycle numbers calculator. Enter your date of birth to get your three numerology Life Cycles, the ages each covers, and the cycle you are in now.
- [Life Path number calculator](https://simplenumerologyapi.com/life-path-number-calculator.md): Free Life Path number calculator. Enter your date of birth to get your Life Path number, calculated the canonical way, with master numbers 11, 22 and 33 kept and a link to what it means.
- [Master number calculator](https://simplenumerologyapi.com/master-number-calculator.md): Free master number calculator. Enter your full name and date of birth to see whether your Life Path, Expression, Soul Urge, Personality, Birthday or Maturity is a master number 11, 22 or 33.
- [Maturity number calculator](https://simplenumerologyapi.com/maturity-number-calculator.md): Free Maturity number calculator. Enter your full birth name and date of birth to get your Maturity number, the Life Path plus the Expression, with master numbers kept.
- [Numerology calculator](https://simplenumerologyapi.com/numerology-calculator.md): Free numerology calculator. Enter your full birth name and date of birth to get your Life Path, Expression, Soul Urge, Personality, Birthday and Maturity numbers, with master numbers kept.
- [Numerology compatibility calculator](https://simplenumerologyapi.com/numerology-compatibility-calculator.md): Free numerology compatibility calculator for couples. Enter two names and dates of birth to get a compatibility score out of 100, a rating, and both Life Path numbers.
- [Personal Day number calculator](https://simplenumerologyapi.com/personal-day-number-calculator.md): Free Personal Day number calculator. Enter your date of birth to get today's Personal Day number in numerology, with your Personal Month and Personal Year.
- [Personal Month number calculator](https://simplenumerologyapi.com/personal-month-number-calculator.md): Free Personal Month number calculator. Enter your date of birth to get this month's Personal Month number in numerology, with your Personal Year and Personal Day.
- [Personal Year number calculator](https://simplenumerologyapi.com/personal-year-number-calculator.md): Free Personal Year number calculator. Enter your date of birth to get your Personal Year, Personal Month and Personal Day numbers for today, and the Universal Year.
- [Personality number calculator](https://simplenumerologyapi.com/personality-number-calculator.md): Free Personality number calculator. Enter your full birth name to get the number its consonants add up to, the side of you other people see first.
- [Phone number numerology calculator](https://simplenumerologyapi.com/phone-number-numerology-calculator.md): Free phone number numerology calculator. Enter a mobile or landline number to reduce its digits to a single numerology number and see what it means.
- [Pinnacle numbers calculator](https://simplenumerologyapi.com/pinnacle-numbers-calculator.md): Free Pinnacle numbers calculator. Enter your date of birth to get your four numerology Pinnacles, the ages each one covers, and the Pinnacle you are in now.
- [Planes of Expression calculator](https://simplenumerologyapi.com/planes-of-expression-calculator.md): Free Planes of Expression calculator. Enter your full birth name to get your physical, mental, emotional and intuitive plane numbers and see which one is strongest.
- [Rational Thought number calculator](https://simplenumerologyapi.com/rational-thought-number-calculator.md): Free Rational Thought number calculator. Enter your name and date of birth to get the numerology number that describes how you think and make decisions.
- [Soul Urge number calculator](https://simplenumerologyapi.com/soul-urge-number-calculator.md): Free Soul Urge number calculator, also called the Heart's Desire number. Enter your full birth name to get the number its vowels add up to, with master numbers kept.
- [Subconscious Self number calculator](https://simplenumerologyapi.com/subconscious-self-number-calculator.md): Free Subconscious Self number calculator. Enter your full birth name to get the numerology number that describes how you react in a crisis: 9 minus your karmic lessons.
- [Wedding date numerology calculator](https://simplenumerologyapi.com/wedding-date-numerology-calculator.md): Free wedding date numerology calculator. Enter any date to get its numerology number, reduced the canonical way with master numbers kept, to pick a wedding or event date.

## Number meanings: Life Path, Expression and Personal Year

- [Expression number 1: the pioneer](https://simplenumerologyapi.com/expression-number-1.md): Expression number 1 meaning in numerology, also called Destiny number 1: the pioneer. Talents, challenges, careers and how to calculate it from your full name.
- [Expression number 11: the visionary](https://simplenumerologyapi.com/expression-number-11.md): Expression number 11 meaning in numerology, also called Destiny number 11: the visionary. Talents, challenges, careers and how to calculate it from your full name.
- [Expression number 2: the diplomat](https://simplenumerologyapi.com/expression-number-2.md): Expression number 2 meaning in numerology, also called Destiny number 2: the diplomat. Talents, challenges, careers and how to calculate it from your full name.
- [Expression number 22: the master builder](https://simplenumerologyapi.com/expression-number-22.md): Expression number 22 meaning in numerology, also called Destiny number 22: the master builder. Talents, challenges, careers and how to calculate it from your full name.
- [Expression number 3: the communicator](https://simplenumerologyapi.com/expression-number-3.md): Expression number 3 meaning in numerology, also called Destiny number 3: the communicator. Talents, challenges, careers and how to calculate it from your full name.
- [Expression number 33: the master teacher](https://simplenumerologyapi.com/expression-number-33.md): Expression number 33 meaning in numerology, also called Destiny number 33: the master teacher. Talents, challenges, careers and how to calculate it from your full name.
- [Expression number 4: the organiser](https://simplenumerologyapi.com/expression-number-4.md): Expression number 4 meaning in numerology, also called Destiny number 4: the organiser. Talents, challenges, careers and how to calculate it from your full name.
- [Expression number 5: the adventurer](https://simplenumerologyapi.com/expression-number-5.md): Expression number 5 meaning in numerology, also called Destiny number 5: the adventurer. Talents, challenges, careers and how to calculate it from your full name.
- [Expression number 6: the caretaker](https://simplenumerologyapi.com/expression-number-6.md): Expression number 6 meaning in numerology, also called Destiny number 6: the caretaker. Talents, challenges, careers and how to calculate it from your full name.
- [Expression number 7: the analyst](https://simplenumerologyapi.com/expression-number-7.md): Expression number 7 meaning in numerology, also called Destiny number 7: the analyst. Talents, challenges, careers and how to calculate it from your full name.
- [Expression number 8: the executive](https://simplenumerologyapi.com/expression-number-8.md): Expression number 8 meaning in numerology, also called Destiny number 8: the executive. Talents, challenges, careers and how to calculate it from your full name.
- [Expression number 9: the humanitarian](https://simplenumerologyapi.com/expression-number-9.md): Expression number 9 meaning in numerology, also called Destiny number 9: the humanitarian. Talents, challenges, careers and how to calculate it from your full name.
- [Life Path number 1: the leader](https://simplenumerologyapi.com/life-path-number-1.md): Life Path 1 meaning in numerology: the independent leader and pioneer. Strengths, challenges, love, career and the Life Path numbers 1 gets on with best.
- [Life Path number 11: the intuitive](https://simplenumerologyapi.com/life-path-number-11.md): Life Path 11 meaning in numerology: the master number of intuition and inspiration. Strengths, challenges, love, career and how 11 relates to 2.
- [Life Path number 2: the peacemaker](https://simplenumerologyapi.com/life-path-number-2.md): Life Path 2 meaning in numerology: the diplomat and partner. Strengths, challenges, love, career and the Life Path numbers 2 gets on with best.
- [Life Path number 22: the master builder](https://simplenumerologyapi.com/life-path-number-22.md): Life Path 22 meaning in numerology: the master builder, the most powerful master number. Strengths, challenges, love, career and how 22 relates to 4.
- [Life Path number 3: the communicator](https://simplenumerologyapi.com/life-path-number-3.md): Life Path 3 meaning in numerology: the creative communicator. Strengths, challenges, love, career and the Life Path numbers 3 gets on with best.
- [Life Path number 33: the master teacher](https://simplenumerologyapi.com/life-path-number-33.md): Life Path 33 meaning in numerology: the master teacher, the rarest Life Path. Strengths, challenges, love, career and how 33 relates to 6.
- [Life Path number 4: the builder](https://simplenumerologyapi.com/life-path-number-4.md): Life Path 4 meaning in numerology: the practical builder. Strengths, challenges, love, career and the Life Path numbers 4 gets on with best.
- [Life Path number 5: the free spirit](https://simplenumerologyapi.com/life-path-number-5.md): Life Path 5 meaning in numerology: the adventurous free spirit. Strengths, challenges, love, career and the Life Path numbers 5 gets on with best.
- [Life Path number 6: the nurturer](https://simplenumerologyapi.com/life-path-number-6.md): Life Path 6 meaning in numerology: the caring nurturer. Strengths, challenges, love, career and the Life Path numbers 6 gets on with best.
- [Life Path number 7: the seeker](https://simplenumerologyapi.com/life-path-number-7.md): Life Path 7 meaning in numerology: the analytical seeker. Strengths, challenges, love, career and the Life Path numbers 7 gets on with best.
- [Life Path number 8: the achiever](https://simplenumerologyapi.com/life-path-number-8.md): Life Path 8 meaning in numerology: the ambitious achiever. Strengths, challenges, love, career and the Life Path numbers 8 gets on with best.
- [Life Path number 9: the humanitarian](https://simplenumerologyapi.com/life-path-number-9.md): Life Path 9 meaning in numerology: the compassionate humanitarian. Strengths, challenges, love, career and the Life Path numbers 9 gets on with best.
- [Personal Year 1: new beginnings](https://simplenumerologyapi.com/personal-year-number-1.md): Personal Year 1 meaning in numerology: a year of new beginnings. What to focus on, what to avoid, love, work and money, and how to find your Personal Year.
- [Personal Year 2: patience and partnership](https://simplenumerologyapi.com/personal-year-number-2.md): Personal Year 2 meaning in numerology: a year of patience and partnership. What to focus on, what to avoid, love, work and money, and how to find your Personal Year.
- [Personal Year 3: expression and joy](https://simplenumerologyapi.com/personal-year-number-3.md): Personal Year 3 meaning in numerology: a year of expression and joy. What to focus on, what to avoid, love, work and money, and how to find your Personal Year.
- [Personal Year 4: work and foundations](https://simplenumerologyapi.com/personal-year-number-4.md): Personal Year 4 meaning in numerology: a year of work and foundations. What to focus on, what to avoid, love, work and money, and how to find your Personal Year.
- [Personal Year 5: change and freedom](https://simplenumerologyapi.com/personal-year-number-5.md): Personal Year 5 meaning in numerology: a year of change and freedom. What to focus on, what to avoid, love, work and money, and how to find your Personal Year.
- [Personal Year 6: home and responsibility](https://simplenumerologyapi.com/personal-year-number-6.md): Personal Year 6 meaning in numerology: a year of home and responsibility. What to focus on, what to avoid, love, work and money, and how to find your Personal Year.
- [Personal Year 7: reflection and study](https://simplenumerologyapi.com/personal-year-number-7.md): Personal Year 7 meaning in numerology: a year of reflection and study. What to focus on, what to avoid, love, work and money, and how to find your Personal Year.
- [Personal Year 8: achievement and power](https://simplenumerologyapi.com/personal-year-number-8.md): Personal Year 8 meaning in numerology: a year of achievement and power. What to focus on, what to avoid, love, work and money, and how to find your Personal Year.
- [Personal Year 9: completion](https://simplenumerologyapi.com/personal-year-number-9.md): Personal Year 9 meaning in numerology: a year of completion. What to focus on, what to avoid, love, work and money, and how to find your Personal Year.

## Optional

- [Running a numerology API in production: keys, versions, errors and quotas](https://simplenumerologyapi.com/blog/numerology-api-in-production.md): What a production numerology integration leans on once the first chart works, from one key per environment, key rotation and version pinning to typed errors, request IDs, quota headers and batch backfills.
- [How to build a numerology app in Python (with a free API)](https://simplenumerologyapi.com/blog/build-a-numerology-app-in-python.md): A step-by-step tutorial for a small Flask numerology app. It takes a name and a birthdate, calls a numerology API, caches the chart, and shows life path, destiny and soul urge numbers.
- [Numerology calculator in JavaScript: write it yourself or call an API?](https://simplenumerologyapi.com/blog/numerology-calculator-in-javascript.md): A correct life path calculator in about ten lines of JavaScript, the conventions that make a full chart harder than it looks, and how to call a numerology API from Node.js instead.
- [Adding numerology to your app in about five lines](https://simplenumerologyapi.com/blog/adding-numerology-to-your-app.md): A practical guide to integrating a numerology API: the request, the response shape, the three fields that surprise people, and how to cache it properly.
- [Karmic debt numbers: 13, 14, 16 and 19](https://simplenumerologyapi.com/blog/karmic-debt-numbers-explained.md): Karmic debts are not values a chart field holds. They are totals passed through during reduction, which is why they are easy to miss and easy to get wrong.
- [Is Y a vowel in numerology?](https://simplenumerologyapi.com/blog/is-y-a-vowel-in-numerology.md): Whether Y counts as a vowel changes the Soul Urge and Personality numbers for millions of names. The tradition genuinely disagrees. Here is what the rules are and why a tool must pick one.
- [Master numbers 11, 22 and 33, and why they break your integer column](https://simplenumerologyapi.com/blog/master-numbers-11-22-33.md): Master numbers stop reduction in Pythagorean numerology, which means a field you typed as a single digit can suddenly return two. Here is where they come from and how to handle them.
- [How to calculate a Life Path number (and the mistake almost everyone makes)](https://simplenumerologyapi.com/blog/how-to-calculate-a-life-path-number.md): The Life Path number is the most-quoted figure in Pythagorean numerology, and the shortcut most calculators use gets it wrong. Here is the correct method, with worked examples.