Interest Calculator
Calculate simple and compound interest on your savings
Last updated: February 2026
Savings Details
£
%
years
Final Amount
£5,675.00
After 3 years
Interest Earned
£675.00
Simple Interest
Savings Breakdown
Principal
£5,000.00
Interest
£675.00
Calculation Details
Interest TypeSimple Interest
Effective Annual Rate (AER)4.50%
Return on Savings13.50%
Simple vs Compound Interest
Simple interest is calculated only on the principal amount, while compound interest is calculated on the principal plus accumulated interest. UK banks typically quote the AER (Annual Equivalent Rate) which shows the true annual return with compounding.
Related calculators
Other free UK tools that follow on from this calculation.
Future Value Calculator
Project how a lump sum or regular contributions grow over time with compound interest.
Present Value Calculator
Discount a future cash flow back to today to see what it is worth right now.
Inflation Calculator
Adjust values for UK CPI inflation to see the real purchasing power of money.
Loan Payment Calculator
Monthly repayments, total interest and amortisation for any personal or car loan.