Compound Interest Calculator
Work out what a lump sum grows to with compound interest.
Final amount
£8,144.47
- Interest earned
- £3,144.47
Assumes interest is compounded once a year with no further contributions.
v1.0 · Reviewed September 2026
How this is worked out
The starting amount is multiplied by (1 + rate) once for each year.
Worked example
- £5,000
- 5%
- 10 years
5,000 × 1.05^10
£8,144.47, including £3,144.47 of interest
Assumptions and limits
- Compounds once a year. Monthly or daily compounding at the same nominal rate gives a slightly higher result.
- No further contributions or withdrawals, and no tax or charges.