About InterestCalc.co.uk
InterestCalc.co.uk provides free, easy-to-use interest calculators for loans, mortgages, savings, credit cards and late payment. There's no sign-up and no cost โ just enter your figures and get a clear answer.
Every calculator is built on standard financial formulas: the annuity (amortisation) formula for loans and mortgages, the compound interest formula for savings and investments, and the statutory method set out in UK law for late-payment interest.
How our figures are kept current
Where a calculator uses an official rate โ such as the Bank of England base rate for statutory interest, or HMRC's interest rate for late tax โ we use the published figure and update it when it changes. UK statutory late-payment interest is the base rate plus 8%; HMRC late-payment interest is the base rate plus 4%.
Important
Our calculators give indicative estimates to help you compare options and plan. They are not financial advice, and a lender's, provider's or HMRC's own figure may differ. Always rely on an official quotation or statement for exact amounts, and seek regulated advice for decisions about borrowing, saving or investing.