Compound interest calculator
See how savings or investments grow when interest is earned on your earlier interest, with optional monthly deposits.
Your balance would be
£32,703
After 10 years.
- What you paid in£25,000
- Interest earned£7,703
| Year | Balance | Paid in | Interest |
|---|---|---|---|
| 1 | £3,507 | £3,400 | £107 |
| 2 | £6,142 | £5,800 | £342 |
| 3 | £8,912 | £8,200 | £712 |
| 4 | £11,824 | £10,600 | £1,224 |
| 5 | £14,885 | £13,000 | £1,885 |
| 6 | £18,102 | £15,400 | £2,702 |
| 7 | £21,484 | £17,800 | £3,684 |
| 8 | £25,039 | £20,200 | £4,839 |
| 9 | £28,775 | £22,600 | £6,175 |
| 10 | £32,703 | £25,000 | £7,703 |
How compound interest works
Interest is added to your balance, and the next round of interest is earned on the new, larger total. Over long periods this snowball effect becomes the biggest part of your growth, which is why starting early matters.
Assumptions
Deposits are added at the end of each month and the rate stays fixed. Investment returns vary year to year and are not guaranteed, and the figures are not adjusted for inflation or tax.
Common questions
What is the difference between AER and the interest rate?
AER is the yearly rate once compounding is included, so it is the best figure for comparing savings accounts. If you enter an AER, choose yearly compounding.
How much will £10,000 grow in 10 years?
At 5% compounded yearly it grows to about £16,289 with no further deposits. Try it above with your own figures.
Is interest on savings taxable?
Most people can earn some interest tax-free through the Personal Savings Allowance, and ISAs are always tax-free.