Numerology Calculator API

What it calculates

One request to POST /v1/charts/pythagorean returns 47 fields:

Other endpoints calculate personal year, month and day cycles and compatibility between two people. See the API reference for all of them.

Try the calculator

The live calculator on the home page calls the real API as you type. For your own app, it is one request:

curl -X POST https://simplenumerologyapi.com/v1/charts/pythagorean \
  -H 'X-API-Key: nk_…' \
  -H 'content-type: application/json' \
  -d '{"first_name":"María","middle_name":"Stefania",
       "last_name":"García López","birthdate":"1990-03-12"}'

{
  "life_path_number": 7,
  "destiny_number": 5,
  "soul_urge_number": 4,
  "personality_number": 1,
  "karmic_debt_numbers": [13],
  "pinnacles": [
    {"stage": 1, "number": 6, "from_age": 0, "to_age": 29},
    "…"
  ],
  "…": "more fields"
}

For code in your language, see the Python and JavaScript quickstarts.

Why use a calculator API instead of writing one

The arithmetic is easy. The conventions are where calculators disagree, and a wrong one shifts every chart:

• Is Y a vowel? Here it is always a consonant by default, and you can choose another rule per request.
• Do master numbers survive reduction? Yes: 11, 22 and 33 are kept. See master numbers.
• How does a name reduce? By default the whole name is summed at once. The per-name (Decoz) method is an option.
• Accents and compound surnames? “María” is read as “maria”, and “García López” works as written.

All of these are documented and frozen, and every response echoes the conventions that produced it. For the full method, read how to calculate a life path number.

Built for production apps

• Deterministic: the same input always gives the same chart, so you can cache it forever.
• Fast: 0.15 ms p99 compute time.
• Private: names and birthdates are never stored or logged.
• Predictable: quota headers on every response, and a 402 when the quota runs out rather than silently wrong data.

Frequently asked questions

Is there a free numerology calculator API?

Yes. The free plan includes 100 calculations a month on every endpoint, with no card required.

Which numbers does the numerology calculator API return?

Life path, destiny, soul urge, personality, maturity, birthday, karmic lessons and debts, hidden passion, planes of expression, pinnacles, challenges, life cycles and more: 47 fields per chart.

Does it support Chaldean numerology?

No. The API is Pythagorean, the system most English-language numerology uses. Pythagorean vs Chaldean explains how the two differ.

How accurate is it?

Every calculation follows a fixed, published set of conventions and is covered by golden tests. Where numerology traditions genuinely disagree, the API documents its default and lets you choose the alternative.