15-Year Mortgage Calculator (UK, 2026)
Work out the monthly repayment on a 15-year mortgage term and see exactly how much interest it saves against the standard 25-year term. Defaults use Bank of England's recent quoted rate.
15 years vs other terms
Same £240,000 loan at 4.32% — what changing the term does to the monthly payment and lifetime interest:
| Term | Monthly | vs 15-year | Total interest | Interest vs 15-year |
|---|---|---|---|---|
| 10 years | £2,467 | +£653 | £55,986 | −£30,530 |
| 15 years (this page) | £1,814 | — | £86,516 | — |
| 20 years | £1,495 | −£319 | £118,834 | +£32,317 |
| 25 years | £1,310 | −£504 | £152,880 | +£66,364 |
| 30 years | £1,191 | −£623 | £188,584 | +£102,067 |
15-year monthly payments by loan size
At 4.32% over 15 years. Each row links to a full cost breakdown for that loan size:
| Loan | Monthly payment | |
|---|---|---|
| £100,000 | £756 | Full £100k cost guide → |
| £150,000 | £1,134 | Full £150k cost guide → |
| £200,000 | £1,512 | Full £200k cost guide → |
| £250,000 | £1,890 | Full £250k cost guide → |
| £300,000 | £2,267 | Full £300k cost guide → |
| £350,000 | £2,645 | Full £350k cost guide → |
| £500,000 | £3,779 | Full £500k cost guide → |
Why choose a 15-year mortgage?
A 15-year mortgage term front-loads the principal: the monthly payment is roughly 40–50% higher than a 25-year term at today's rates, but the lifetime interest bill is close to half. That's not a rate trick — it's pure amortisation. Interest accrues on the outstanding balance, and a 15-year schedule clears the balance so fast that there's much less balance left to charge interest on each year.
In the UK, 15-year terms are most popular with remortgagors — people five-to-ten years into a 25- or 30-year mortgage who now earn more, have built equity, and want to be mortgage-free in their fifties. (If you've searched for the American "15-year fixed", note the UK equivalent is a 15-year term; UK fixed-rate periods are separate, typically 2, 5 or 10 years — the comparison calculator handles fixes and fees.)
Before committing, check the higher payment survives the lender's stress test and still leaves room for emergencies — a 20- or 25-year term with consistent overpayments is the more flexible route to the same destination.
How it's calculated
The monthly payment uses the standard amortising-loan formula used by every UK lender:
M = P × (i × (1+i)n) / ((1+i)n − 1)
where P is the loan (price minus deposit), i is the monthly rate (annual ÷ 12) and n is 180 payments (15 years × 12). Interest accrues on the outstanding balance, which is why shortening the term saves so much — see the full explanation on the main mortgage calculator.
Frequently asked questions
How much is a 15-year mortgage on £200,000?
At 4.32%, a £200,000 loan over 15 years costs about £1,512 a month with roughly £72,097 total interest. The same loan over 25 years is about £1,091 a month but £127,399 in interest — the 15-year term roughly halves the lifetime interest.
How is a 15-year mortgage payment calculated?
It uses the standard amortising formula: monthly payment = P × i × (1+i)^n / ((1+i)^n − 1), where P is the loan, i is the monthly rate (annual ÷ 12) and n is 180 payments (15 × 12). This calculator runs that formula server-side with your inputs.
Can a first-time buyer take a 15-year mortgage term?
Yes, if your income supports the higher monthly payment under the lender's affordability stress test. In practice most UK first-time buyers choose 25–35 years and overpay later; 15-year terms are more common at remortgage, once equity has built up.
Do shorter mortgage terms get lower interest rates?
Rates are priced mainly by loan-to-value and product type, not term length — but shorter terms cut lifetime interest dramatically because the balance amortises faster. Some lenders also price 10- and 15-year fixes differently from 2- and 5-year fixes.
Related calculators & guides
- Mortgage calculator — any term, with a full rate × term payment matrix
- Mortgage comparison & overpayment calculator — products side-by-side, fees and overpayments modelled
- Affordability calculator — how much could you borrow?
- Stamp duty calculator — SDLT, LBTT and LTT with all surcharges
- How overpayments bend your equity curve
- How a 25-year mortgage actually amortises
This calculator is a general-information tool, not a mortgage offer or financial advice. Your actual rate depends on lender, LTV, credit profile, product fees and stress-test outcomes. Speak to a regulated mortgage adviser before committing. Source for default rate: Bank of England's monthly effective interest rates.