Compound Interest Calculator with Growth Chart

Free tool

Compound Interest Calculator

See how savings or investments grow once interest starts earning interest — and how much of the final pot is growth rather than money you paid in.

Currency

What you're putting in

Starting amount

Monthly contribution

Set to 0 to see growth on the starting amount alone.

Growth assumptions

Annual interest rate

Time invested

yrs

Compounding frequency

Inflation rate

Illustrative only, assuming a steady return with contributions added at the end of each month. “Today’s money” restates the balance at your inflation rate so you can see what it would actually buy. Real returns vary, and this ignores tax and fees.

Balance after 20 years

£150,425

You paid in: £65,000
Interest earned: £85,425
In today's money (2.5% inflation): £91,800

Total balance In today’s money Money you paid in

Interest as % of pot

56.8%

Money multiplied by

2.31×

Real return after inflation

4.39%

Lost to inflation

£58,625

Without any interest

£65,000

Extra from compounding

£85,425

Along the way

Year 5 — £22,084 in today's money: £24,986
Year 10 — £41,653 in today's money: £53,320
Year 15 — £64,548 in today's money: £93,485
Year 20 — £91,800 in today's money: £150,425

See what a starting pot plus regular monthly contributions could become once interest starts earning interest. Choose the rate, timeframe and compounding frequency — annually, quarterly, monthly or daily — and add an inflation rate and the chart plots three lines: the money you paid in, the nominal balance, and what that balance is really worth in today's money.