Compound Interest Calculator UK
See how your savings grow when interest is earned on interest – with monthly contributions and compounding.
Calculate loan interest
What is this calculator?
This loan calculator works out the monthly payment and total interest from the amount, the interest rate (APR) and the term.
It suits personal loans, car finance, consumer credit and student loans – any loan repaid in equal monthly instalments.
How to use this calculator
- Enter the required details in the form above.
- Click the “Calculate” button.
- Review the results and compare your options.
- Download the result as CSV or share it as a link.
Frequently asked questions – Compound Interest Calculator UK
The calculator uses standard financial formulas – the annuity (PMT) formula for loans and the compound interest formula for savings. Results are indicative; a lender's or creditor's final figure may differ slightly, for example because of rounding conventions.
Yes. Every calculator on InterestCalc.co.uk is completely free, with no sign-up or registration. You can use it as many times as you like.
Your calculations are saved only in your own browser (local storage) so you can come back to them. Nothing is sent to a server or shared with third parties.
Yes. There's a “Share result” button that creates a link to your calculation, and you can export a repayment schedule as a CSV file for Excel.
A lender's final offer can include individual terms – a personal rate, fees or a rate cap – that a general calculator can't know. Use the result as an indicative comparison figure and always ask the lender for a written quotation.