CompoundCalc is a small, free calculator site built around one idea: a compound interest estimate should show its working. Every result here comes with the year-by-year table, the split between money paid in and interest earned, and the effective annual rate — so you can check the arithmetic instead of taking it on faith.
How it works
All calculations run in your browser, using the standard compound interest formula A = P(1 + r/n)nt for lump sums and the matching annuity formula for monthly contributions, which are assumed to land at the end of each month. Nothing you type is sent to a server, stored, or shared — there is no account to create and nothing to sign up for.
What it is not
CompoundCalc is an educational estimation tool. It is not a bank, a broker or a financial adviser, and nothing on this site is financial advice. Rates used in examples — including the recurring 7% — are hypothetical illustrations picked for clean arithmetic. They are not the rates of any real product, and no return is promised or implied. Real investments can lose value. For decisions about your own money, consult a qualified professional.
Part of a small tool family
CompoundCalc is one of a set of free single-purpose tools by ORBITFRAME; the footer of every page links to its sister sites. A Pro tier ($9/mo) is planned — scenario comparisons, CSV export and saved plans — but it is not available yet and no payment is taken anywhere on this site.