Compare up to four UK mortgages side by side: different rates, fixed periods, terms, overpayments, and arrangement fees. The calculator models the realistic UK product structure — initial fixed rate followed by a revert to SVR or product-transfer rate — and gives you total lifetime interest, monthly payment and balance trajectory for each scenario. Particularly useful when weighing a low 2-year fix against a higher 5-year fix that locks in stability through the 2026 cliff.
Mortgage Comparison
Up to four UK mortgages side by side. Each scenario models the initial fix, the post-fix revert rate (SVR cliff), and any overpayment — so you see the lifetime cost, not just month-1 payment.
My scenarios (0/10)
Save snapshots of your inputs to switch between scenarios (e.g. “65% LTV, higher-rate” vs “75% LTV, basic-rate”). Stored in your browser only — no login needed.
Headlines
2-yr fix, no overpayment
£1,169/mo
Total interest: £230,572
Term: 25.0 yrs
5-yr fix
£1,134/mo
Total interest: £208,934
Term: 25.0 yrs
5-yr fix + £200 overpayment
£1,134/mo
Total interest: £173,855
Term: 24.9 yrs
Balance over time
Each scenario's outstanding balance, every 6 months.
Total interest paid
Lifetime interest by scenario.
Use these together
Calculators that pair naturally with this one.
Related guides
Plain-English explainers for the rules behind this calculator.
Frequently asked questions
Answers to the questions UK property investors most often have about this tool and the underlying rules.
- What does the "revert rate" mean?
- Most UK mortgages are taken on an initial fixed rate (typically 2 or 5 years) and then revert to the lender's Standard Variable Rate (SVR) when the fix ends. SVRs in 2026 typically sit at 7.5-9.5%. Most borrowers refinance or take a "product transfer" with the same lender before reverting — but the revert rate is what your contract specifies and what lenders use for stress-testing.
- Are mortgages cheaper at higher LTV?
- No. Lower LTV (60-65%) gets the best rates because the lender's exposure is lower. 75% LTV pricing is typical for BTL. 80-85% LTV pricing carries premium of 0.3-0.5 percentage points. 90-95% LTV products are limited and significantly more expensive.
- Should I overpay or save the difference?
- Mathematically: overpay if your mortgage rate exceeds your post-tax savings rate. In 2026, with mortgage rates at 4.5-6% and tax-free ISA returns at 4-5%, the maths usually favours overpayment. But liquidity matters — overpaid principal is locked in the property until refinance or sale. The calculator shows lifetime interest saved by your monthly overpayment.