Compound Interest Calculator

Project the future value of a savings or investment account. Type a starting balance, an optional recurring contribution, an annual rate, a term, and a compounding frequency — the future value, total interest, and a year-by-year schedule appear live. Pure client-side math, no upload.

Starting balance Regular contribution Contribution period Contribution timing Annual rate (%) Term (years) Compounding

Future value —

Total interest —

Total contributed —

Effective annual rate —

Formula —

Contributions Interest earned

Year-by-year schedule

Year	Contributions this year	Interest this year	Total contributions	Total interest	End-of-year balance

How it works

The future value of the starting balance is FV = P · (1 + r/n)^n·t, and the future value of a regular contribution of PMT per compounding period is PMT · [((1 + r/n)^n·t − 1) / (r/n)]. Here r is the annual rate as a decimal, n is the number of compounds per year, and t is the term in years. For a start-of-period contribution, the contribution term is multiplied by (1 + r/n).

The schedule is built by chaining closed-form future-value evaluations starting from the previous row's end balance, so the year-by-year numbers add up to the final total.