Integration API

DigiCalcs Integration API

Add DigiCalcs's everyday calculators to your app or website. 4,600+ health, finance, and lifestyle tools accessible via REST API.

Get Your API Key →View pricing OpenAPI spec

Try it live

Choose a calculator, add your API key and inputs, and see a live response.

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Authentication

Every API request needs an API key in the X-API-Key header. Manage your keys in the API dashboard →

curl -X POST https://www.digicalcs.com/api/v1/calculate \
  -H "Content-Type: application/json" \
  -H "X-API-Key: YOUR_API_KEY" \
  -d '{"calculator": "percentage", "inputs": {"value": 200, "percentage": 15}}'

Calculate Endpoint

POST/api/v1/calculate

Request body

{
  "calculator": "compound-interest",
  "inputs": {
    "principal": 1000,
    "rate": 5,
    "years": 10,
    "compounding": "annually"
  }
}

Response

{
  "success": true,
  "calculator": "compound-interest",
  "result": {
    "results": {
      "futureValue": { "value": 1628.89, "label": "Future Value", "unit": "$" },
      "totalInterest": { "value": 628.89, "label": "Total Interest", "unit": "$" }
    },
    "explanation": "With $1,000 at 5% compounded annually for 10 years, the investment grows to $1,628.89."
  },
  "cached": false,
  "timestamp": "2026-05-14T10:30:00.000Z"
}

API Reference

GET/api/v1/calculators

List all available calculators. No API key required. Supports ?category=math and ?q=bmi query filters. Returns { total, calculators: [{ slug, title, description, category, subcategory, hasFormula }] }.

GET/api/v1/calculators/:slug

Get full schema/info for a specific calculator, including formula and usage instructions. No API key required. Returns 404 if the slug is unknown.

POST/api/v1/calculate

Runs a calculation. Requires X-API-Key. Body: { calculator: string, inputs: object }. Responses are cached for 10 minutes per unique input combination.

Code Samples

curl -X POST https://www.digicalcs.com/api/v1/calculate \
  -H "Content-Type: application/json" \
  -H "X-API-Key: YOUR_API_KEY" \
  -d '{"calculator": "bmi", "inputs": {"weight": 70, "height": 175, "unit": "metric"}}'

Rate Limits

Plan	Requests / Day	API Keys
Hobby (Free)	100	1
Developer	10,000	3
Business	100,000	10
Enterprise	Unlimited	50

See the full API pricing page for plan details.

Error Codes

Code	Description
401	Missing or bad API key
403	API key revoked
404	Calculator not found
429	Too many requests

Get started in minutes

Create an API key in the dashboard and add everyday calculators to your app.

Get Your API Key →