Savings Goal API
Personal-savings planning maths as an API, computed locally and deterministically. The future endpoint computes the future value of regular saving — FV = initial·(1+r)^n + deposit·((1+r)^n − 1)/r with the rate compounded monthly — and breaks it into the total you put in and the interest earned. The goal endpoint works backwards: the monthly deposit needed to reach a target by a date, (target − initial·(1+r)^n)·r / ((1+r)^n − 1), and tells you when an initial sum already grows to the target by itself. The emergency endpoint sizes an emergency fund as a number of months of expenses (3–6 is the usual advice), reports the shortfall against current savings and, with a monthly saving amount, how many months it takes to get there. Everything is computed locally and deterministically, so it is instant and private. Ideal for personal-finance, budgeting and fintech app developers, savings-goal and money-coaching tools, and banking dashboards. Pure local computation — no key, no third-party service, instant. Live, nothing stored. Estimates, not financial advice. 3 endpoints. This is savings planning; for loans and mortgages use a loan API and for NPV/IRR use a finance-calc API.
api.oanor.com/savings-api