#loan

Loan and mortgage amortization maths as an API, computed locally and deterministically. The payment endpoint computes the fixed monthly payment of a fully-amortizing loan, M = P·r·(1+r)ⁿ / ((1+r)ⁿ − 1), where r is the annual rate divided by twelve and n is the number of monthly payments, and returns the total paid over the life of the loan, the total interest and the share of every dollar that goes to interest. The schedule endpoint breaks any single payment into its interest and principal parts, shows the remaining balance after it, and the cumulative interest and principal paid so far — so you can see exactly how a mortgage shifts from interest to equity over time. The affordability endpoint inverts the formula to give the largest principal a chosen monthly budget can service at a given rate and term. The term is entered as years or months, and zero-interest loans are handled. Everything is computed locally and deterministically, so it is instant and private. Ideal for fintech, real-estate, banking and personal-finance app developers, mortgage and auto-loan calculators, and finance education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is loan amortization; for break-even and CVP analysis use a break-even API and for savings-goal projections use a savings API.

api.oanor.com/loan-api

Common money math as an API. Calculate a loan: its monthly payment, total interest and total cost — with an optional full amortization schedule and the effect of extra monthly payments. Break down a mortgage into PITI (principal & interest, property tax, insurance, PMI and HOA) from a purchase price and down payment. Project compound interest and savings growth with optional recurring contributions (future value, total contributions, interest earned). And compute ROI on an investment, with annualised return when you supply the holding period. Every calculation is exact, deterministic and instant — pure local math, no third-party service and nothing stored. Live. 5 endpoints. Built for loan and mortgage calculators, savings and retirement planners, fintech tools and budgeting apps. Distinct from market-data and bank-data services. No upstream key.

api.oanor.com/fincalc-api