Business Loan Repayment Calculator
Calculate monthly repayments and total interest on a business loan.
About this calculator
Before signing a business loan, you need two numbers: the monthly repayment your cash flow must absorb, and the total interest — the true cost of the money. This calculator computes both using the standard amortisation formula that banks use for fixed-rate repayment loans, where each month you pay the same amount and the interest portion shrinks as the balance falls.
The formula
Worked example
Borrowing £25,000 at 7.5% over 5 years:
- Monthly payment = £500.95
- Total repaid = £500.95 × 60 = £30,057
- Total interest = £5,057
Common mistakes
- Comparing loans on monthly payment alone — a longer term lowers the payment but raises the total interest.
- Ignoring arrangement fees, which effectively raise the interest rate.
- Confusing a flat rate with an APR — a 5% flat rate is roughly a 9–10% APR equivalent.
Frequently asked questions
Assumptions & limitations
Fixed interest rate for the whole term, equal monthly instalments, interest compounded monthly, no fees. Not financial advice.
Sources & verification
- MoneyHelper (Money and Pensions Service) — loans and borrowing — Government-backed guidance; uses the standard amortisation formula shown above
All sources last accessed 24 July 2026.
Spotted an error or an out-of-date figure? Report it — corrections are prioritised over all other work (see our corrections policy).