See what a savings pot or investment actually grows to — and how much of that is simple interest versus compounding.
The Interest Calculator shows what a sum of money earns as simple interest (rate applied only to the starting amount) and as compound interest (rate applied each year to the running total including previous interest). Seeing both next to each other is the point — the difference is small in year one and gets dramatic somewhere between year five and year twenty, which is where most savings and investment decisions live.
Reach for this when comparing savings accounts (which one really pays more?), sanity-checking a broker's projection, or explaining to yourself why starting a pension at 25 is not the same as starting one at 45. Real banks often compound monthly or daily rather than annually, so treat the compound figure here as a slight underestimate of a real savings account and a slight overestimate of a real simple-interest loan.
Simple = on principal only. Compound = on principal plus earned interest, resulting in faster growth.
Annually in this calculator. Banks may compound monthly or daily for slightly higher returns.
Yes, use decimals like 2.5 for two and a half years.
For savings, compound earns more. For loans, simple costs less.
Find out what a personal, car or student loan will cost you per month — and how much of it is interest, not principal.
See what a house at a given price actually costs each month — and how much you'll pay in interest over 15 vs 30 years.
Solve the three percentage questions people actually get stuck on: X% of Y, what percent X is of Y, and the change from X to Y.
Work out what to charge with VAT on top, or pull the VAT back out of a gross price — the two calculations freelancers and shoppers actually need.