Interest Calculator

Calculate simple and compound interest on your savings

Last updated: February 2026

Savings Details

Principal Amount

Interest Rate (AER)

Time Period

years

Interest Type

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.