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Free Old vs New Income Tax Regime Comparison API (2026)

Returns the tax under one regime per call, so a comparison is two calls on the same income. Old-regime deductions such as 80C, 80D and HRA are not separate inputs: subtract them from income before calling with regime=old.

Interactive API Playground & Live Test

GET/api/v1/income-tax

Query Parameters

Gross annual income in ₹; for the old regime, subtract 80C, 80D and other deductions first

old | new (default: new). Call once with each to compare

curl -X GET "https://fincalculator.in/api/v1/income-tax?income=1500000&regime=old" \
  -H "Accept: application/json"
Live JSON Response (HTTP 200 OK)
Click "Execute Live API Request" below...

Request Parameters Schema

ParameterTypeRequiredDescription / Notes
incomenumberRequiredGross annual income in ₹; for the old regime, subtract 80C, 80D and other deductions first
regimestringOptionalold | new (default: new). Call once with each to compare

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Frequently Asked Questions (FAQs)

Is the Free Old vs New Income Tax Regime Comparison API free to use in production apps?
Yes! All FinCalculator REST APIs are completely free, zero-auth, open-CORS, and edge-cached for high performance across global web and mobile applications.
What is the rate limit for /api/v1/income-tax?
Endpoints are cached at the edge for 24 hours. There are no restrictive rate limits for standard web traffic and mobile applications.