Business & SME APIWeb Calculator UI

Free GST Input Tax Credit (ITC) Calculator API (2026)

API for small businesses, CA portals, and invoicing software to calculate net GST liability and ITC carryforward.

Interactive API Playground & Live Test

GET/api/v1/gst-itc

Zero Auth • Open CORS

Query Parameters

salesnumber • required

Sales amount excl. GST in ₹

salesRatenumber • required

Sales GST rate % (0, 5, 18, 40)

purchasesnumber • required

Purchases amount excl. GST in ₹

purchasesRatenumber • required

Purchases GST rate %

interstateboolean • optional

Set "true" for IGST, "false" for CGST+SGST

curl -X GET "https://fincalculator.in/api/v1/gst-itc?sales=1000000&salesRate=18&purchases=600000&purchasesRate=18&interstate=false" \
  -H "Accept: application/json"

Live JSON Response (HTTP 200 OK)

Click "Execute Live API Request" below...

Request Parameters Schema

Parameter	Type	Required	Description / Notes
sales	number	Required	Sales amount excl. GST in ₹
salesRate	number	Required	Sales GST rate % (0, 5, 18, 40)
purchases	number	Required	Purchases amount excl. GST in ₹
purchasesRate	number	Required	Purchases GST rate %
interstate	boolean	Optional	Set "true" for IGST, "false" for CGST+SGST

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Frequently Asked Questions (FAQs)

Is the Free GST Input Tax Credit (ITC) Calculator 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/gst-itc?

Endpoints are cached at the edge for 24 hours. There are no restrictive rate limits for standard web traffic and mobile applications.