FinCalc API
8 financial calculator endpoints for developers
Start new thread
Robert Pringle

FinCalc API - 8 financial calculator endpoints for developers

by•
Stop reimplementing financial math. FinCalc API gives developers 8 production-ready REST endpoints: Amortization, Mortgage, Compound Interest, ROI, NPV, IRR, Break-Even, and Depreciation. Returns structured JSON. Inputs as query params. Stateless - no data stored. Sub-50ms responses. Free tier: 50 calls/day. Paid plans from $9.99/mo.

Add a comment

Replies

Best
Robert Pringle
Maker
📌
Hey PH! I built this because I kept writing the same financial math functions across different projects. Amortization especially - getting the rounding right on a 30-year schedule is fiddly. FinCalc API is a simple REST API that handles all the common financial calculations developers need. It's stateless (no data stored), fast (sub-50ms), and has a generous free tier for prototyping. Happy to answer any questions about the implementation (FastAPI + Hetzner VPS + RapidAPI for auth/billing) or the math behind any of the endpoints. What financial calculations do you wish existed as an API? Would love to add them!