Example result based on the prefilled values.
Monthly
£197.54
Total Repaid
£11,852.43
Interest
£1,852.43
Continue your plan
Useful next calculations
Rates & sources
Standard amortisation formulas used across UK lenders. Interest rates move daily — confirm with your lender or broker.
Source: Bank of England — Statistics — check the linked guidance and any live quote before acting.
When to use this calculator
- Before comparing lenders, brokers, or repayment options.
- When you want to test how a different deposit, rate, or term changes affordability.
- When you need a quick estimate before using a formal quote or agreement in principle.
- When you are stress-testing your budget against a potential rate rise to see the impact on monthly payments.
- When you want to understand the full cost of borrowing — not just the monthly figure — before you commit.
Example: comparing the cost of a standard repayment plan
Use these sample inputs as a quick scenario test, then change one variable at a time to compare outcomes.
Loan amount
£12,000
Interest rate
6.9%
Repayment term
4 years
Goal
Balance affordability with lower total interest
This kind of example is useful because it shows the trade-off most borrowers face: manageable payments versus the extra interest that appears when the same debt is spread longer.
How to read your results
Monthly
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Total Repaid
This is the headline outcome of the calculation, but it is most useful when read alongside the supporting metrics below it rather than in isolation. Try changing one input at a time and watching how this total moves to understand which driver has the biggest impact.
Interest
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Method & assumptionsAuthoritative sources
This calculator uses a standard amortising loan formula to compute fixed monthly repayments over your chosen term. Each payment is split between interest — charged on the remaining balance — and principal reduction. In the early months of a loan, a larger portion of each payment covers interest; as the balance falls, more of each payment goes toward reducing the debt. The APR figure you enter is divided by 12 to derive a monthly rate for this calculation. The result is a useful planning guide, but the exact repayment schedule from your lender may differ marginally due to rounding, payment date adjustments, or how they handle the first partial month. Always refer to your lender's official quotation for binding figures.
Common mistakes
- !Mixing up loan amount and property value, which can distort affordability and LTV.
- !Using a headline rate but forgetting fees, insurance, taxes, or repayment type.
- !Testing only one term length instead of comparing the payment and total cost together.
- !Forgetting that a repayment mortgage and an interest-only mortgage produce very different monthly figures and total costs.
- !Not accounting for the impact of a rate revert after an introductory fixed period ends, which can sharply increase payments.
What to do next
- Compare offers using the same amount and term, then check total repayable rather than judging the monthly payment alone.
- Add any arrangement fees and read the early-settlement terms before treating the estimate as the full borrowing cost.
- Test a shorter term to see whether a higher monthly payment produces a worthwhile reduction in total interest.
Frequently asked
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