Quickly calculate simple interest earned or owed on a principal amount over a given period at a fixed interest rate.
🇬🇧 Simple Interest Result
Total interest
£975
Total amount (P + I)
£5,975
Principal
£5,000
Rate applied
6.5%
A simple interest calculator computes the interest earned or owed on a principal amount using a flat rate applied to the original sum — not to accumulated interest. It is the most straightforward interest model and is commonly used for short-term loans, fixed deposits, and treasury bills in United Kingdom.
Enter the principal amount, the annual interest rate, and the time period in years. The calculator returns the total interest, the final amount (principal + interest), and a breakdown of interest per year, month, and day.
A United Kingdom fixed deposit of £5,000 at 6.5% simple interest over 3 years earns £975 in interest. Enter your own figures above.
Simple interest is used for short-term loans, car loans in some markets, savings bonds, and treasury bills. It is also used to calculate daily interest on some current accounts and mortgages.
For savings, compound interest is better because interest builds on itself. For borrowing, simple interest is cheaper because you only pay interest on the original principal.
UK interest rates are influenced by the Bank of England base rate. Personal loan rates typically range from 3%–30% APR depending on your credit score.
Popular lenders in United Kingdom include Barclays, Lloyds, NatWest, HSBC, Santander. Always compare rates from multiple providers before committing.