Mortgage Calculator
Compare interest-only and repayment mortgage costs, with a rate stress test.
Introduction
Who this is for: Anyone financing a property purchase.
Why it matters: Interest-only keeps monthly payments low but repays nothing — the full balance is still due at term end. Repayment costs more monthly but clears the debt. Most BTL is interest-only; most residential is repayment.
Typical scenario: A landlord comparing interest-only against repayment on a £180,000 loan, and checking affordability if rates rise 2%.
- Budgeting on the initial fixed rate rather than the likely revert rate.
- Choosing interest-only without a credible repayment strategy for the capital.
- Ignoring product fees, which on smaller loans materially affect the true rate.
Inputs
Loan
years
Analysis
A £188,995 loan at 5.2% over 25 years costs £1,127 monthly on repayment, or £819 interest-only. Interest-only saves £308 a month but leaves the full £188,995 outstanding at term end.
This analysis provides context, not financial advice. Consult a qualified adviser before making investment decisions.
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Sensitivity
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Live Results
Repayment Monthly
£1,127
Interest-Only Monthly
£819
Loan Amount
£188,995
Repayment at +2%
£1,360