Compare the differences in monthly payments and total costs between two mortgages. Useful for:
- Choosing between fixed and variable rate mortgages
- Comparing products from different lenders
- Deciding whether to remortgage to a better deal
- Understanding how a shorter term affects total interest paid
Trying to compare the full length of a mortgage (e.g. 25 years) would be unrealistic, because the interest rates would differ throughout the lifetime.
This tool works best by comparing two fixed rate mortgages over the same length of time.
Mortgage 1
Mortgage 2
Summary
Per month
Mortgage 1 will cost you £1,584 per month, while Mortgage 2 will cost you £1,754 per month.
Mortgage 1 is £170 cheaper per month.
For 5 years
The interest you will pay after 5 years for Mortgage 1 is £56,325, compared to £70,967 for Mortgage 2 after 5 years.
Mortgage 1 is £14,642 cheaper over 5 years.
Mortgage lifetime
Over the lifetime of Mortgage 1, you will pay £175,054 for interest, whereas for Mortgage 2 you will pay £226,132.
Mortgage 1 is £51,078 cheaper over the lifetime of the mortgage.
| Mortgage 1 | Mortgage 2 | Difference | |
|---|---|---|---|
| Monthly mortgage payment: | £1,584 | £1,754 | -£170 |
| Interest paid over 5 years: | £56,325 | £70,967 | -£14,642 |
| Total interest paid: | £175,054 | £226,132 | -£51,078 |
Mortgage 1
£300,000 over 25 years at 4%
| Interest rate change | Interest rate | Monthly mortgage payment | Change in monthly mortgage payments |
|---|---|---|---|
| -3% | 1% | £1,131 | -£453 |
| -2% | 2% | £1,272 | -£312 |
| -1% | 3% | £1,423 | -£161 |
| - | 4% | £1,584 | - |
| +1% | 5% | £1,754 | +£170 |
| +2% | 6% | £1,933 | +£349 |
| +3% | 7% | £2,120 | +£537 |
| +4% | 8% | £2,315 | +£732 |
| +5% | 9% | £2,518 | +£934 |
Mortgage 2
£300,000 over 25 years at 5%
| Interest rate change | Interest rate | Monthly mortgage payment | Change in monthly mortgage payments |
|---|---|---|---|
| -3% | 2% | £1,272 | -£482 |
| -2% | 3% | £1,423 | -£331 |
| -1% | 4% | £1,584 | -£170 |
| - | 5% | £1,754 | - |
| +1% | 6% | £1,933 | +£179 |
| +2% | 7% | £2,120 | +£367 |
| +3% | 8% | £2,315 | +£562 |
| +4% | 9% | £2,518 | +£764 |
| +5% | 10% | £2,726 | +£972 |
Chart
Note:
The calculations displayed in this chart are made under the assumption that the mortgage rates remain constant over 5 years. Whereas, in reality they are likely to change when you remortgage.
- When should I use this calculator?
- Any time you're weighing up two mortgage products. That might be a fixed rate versus a tracker, two competing lender offers, a remortgage versus staying put, or just wanting to see what a shorter comparison period would cost you each month in the summary.
- What costs aren’t included in this comparison?
- Monthly payments and total interest only, so you'll need to account for these separately:
- Lender arrangement or product fees
- Valuation and survey fees
- Conveyancing (solicitor) fees
- Early repayment charges (ERCs) if you exit a deal early
- Buildings and contents insurance
- What’s the difference between a fixed and variable rate mortgage?
- A fixed-rate mortgage keeps your interest rate and monthly payment the same for an agreed period, usually 2 or 5 years. Variable rates (trackers and SVRs) move with the Bank of England base rate or the lender's own rate, so your payments can go up or down. Variable rates are often lower to begin with, but you're taking on rate risk in exchange.
- When should I consider remortgaging?
Start looking about 3–6 months before your deal ends; most lenders let you lock a new rate in advance so you switch over seamlessly.
It's also worth checking your current LTV. If house prices have risen or you've paid down a good chunk of the mortgage, you may now sit in a cheaper LTV band. Run both scenarios through this calculator before committing, then compare them in the summary and chart.
- How do early repayment charges affect my comparison?
- If you switch before your fixed term ends, your lender will usually charge an ERC, typically 1–5% of the outstanding balance. That can be thousands of pounds, so if you're comparing staying versus switching early, you need to add that figure to the cost of the new deal, otherwise the comparison is misleading.
Find out how much your monthly mortgage repayments will be based on the property price, mortgage length and your deposit amount.
Mortgage Calculator