Mortgage Calculator UK 2026, Monthly Repayments, Interest & Overpayments
Calculate UK mortgage repayments, total interest, and LTV ratio. Compare repayment vs interest-only, see the impact of overpayments, and view a year-by-year amortisation schedule.
A UK repayment mortgage typically runs over 25-35 years at a fixed or tracker rate. In 2026, average 2-year fixes are around 4.5% and 5-year fixes around 4.3%. Your monthly payment is principal + interest, calculated so the balance hits zero at the end. Interest-only mortgages charge only interest; the balance stays whole.
Enter loan size, rate, and term to see your monthly payment and total interest.
Mortgage Calculator
£1,501
Monthly payment
£180,224
Total interest
£450,224
Total repaid
90.0%
LTV ratio
Amortisation Schedule
| Year | Balance | Interest Paid | Total Paid |
|---|---|---|---|
| 1 | £264,019 | £12,028 | £18,009 |
| 2 | £257,763 | £23,780 | £36,018 |
| 3 | £251,219 | £35,246 | £54,027 |
| 4 | £244,375 | £46,411 | £72,036 |
| 5 | £237,216 | £57,261 | £90,045 |
| 6 | £229,729 | £67,783 | £108,054 |
| 7 | £221,898 | £77,960 | £126,063 |
| 8 | £213,706 | £87,778 | £144,072 |
| 9 | £205,139 | £97,220 | £162,081 |
| 10 | £196,178 | £106,268 | £180,090 |
| 25 | £0 | £180,224 | £450,224 |
How Mortgages Actually Work
A mortgage is a loan secured against a property. If you stop paying, the lender can repossess the house. That security is why mortgage rates are lower than personal loan rates, the bank's risk is backed by a physical asset worth hundreds of thousands of pounds.
The critical thing most people don't realise: in the early years, you're mostly paying interest. On a £270,000 mortgage at 4.5% over 25 years, your first monthly payment of £1,501 splits roughly £1,013 to interest and £488 to capital. You're paying the bank twice as much as you're paying off your loan. This ratio gradually inverts, by year 20, most of each payment goes to capital. That's the amortisation curve.
This is also why overpayments early in the mortgage are so powerful. Every extra pound you pay goes straight to capital, reducing the balance that generates interest for the remaining 20+ years. A £100/month overpayment in year 1 has vastly more impact than the same overpayment in year 20.
LTV Bands and What They Mean for Your Rate
| LTV Band | Deposit (on £300k) | Typical 5yr Fixed Rate | Availability |
|---|---|---|---|
| 95% LTV | £15,000 (5%) | 5.0-5.5% | Limited, fewer lenders, stricter criteria |
| 90% LTV | £30,000 (10%) | 4.3-4.8% | Good, most lenders offer this |
| 85% LTV | £45,000 (15%) | 4.0-4.5% | Good, better rates unlock |
| 80% LTV | £60,000 (20%) | 3.8-4.3% | Very good, a key threshold |
| 75% LTV | £75,000 (25%) | 3.5-4.0% | Excellent, significantly better rates |
| 60% LTV | £120,000 (40%) | 3.3-3.8% | Best available rates |
Rates are indicative for 2026 UK market. Your actual rate depends on credit score, income, lender, and product type. Compare deals using a whole-of-market mortgage broker.
The Power of Overpayments
On a £250,000 mortgage at 4.5% over 25 years (monthly payment: £1,390), here's what overpaying does:
| Monthly Overpayment | Interest Saved | Years Saved | Paid Off In |
|---|---|---|---|
| £0 (no overpayment) | — | — | 25 years |
| £50/month | ~£9,500 | ~2 years | ~23 years |
| £100/month | ~£17,500 | ~3.5 years | ~21.5 years |
| £200/month | ~£30,000 | ~6 years | ~19 years |
| £500/month | ~£55,000 | ~11 years | ~14 years |
Important: most lenders allow up to 10% overpayment per year without early repayment charges. Check your mortgage terms before overpaying more than this.
The True Cost of Buying a Property
The deposit and mortgage payments are the obvious costs. Here's what catches first-time buyers off guard:
| Cost | Typical Range | When Paid |
|---|---|---|
| Stamp Duty (SDLT/LBTT/LTT) | £0 – £15,000+ | Within 14 days of completion |
| Solicitor / conveyancer | £800 – £1,500 | On completion |
| Survey (HomeBuyer or Building) | £250 – £700 | Before exchange |
| Mortgage arrangement fee | £0 – £2,000 | On application or added to loan |
| Valuation fee | £0 – £500 | On application (often free) |
| Moving costs | £300 – £1,500 | Moving day |
| Furniture and repairs | £1,000 – £5,000+ | After moving in |
Common Mistakes
Only comparing the interest rate
A 3.8% rate with a £1,999 fee can cost more than a 4.0% rate with no fee over a 2-year fix. Compare the total cost including fees, not just the headline rate.
Staying on the SVR after the fixed period ends
SVR is typically 1-3% higher than competitive fixed rates. Set a calendar reminder 3 months before your fixed deal ends and start shopping for a remortgage.
Stretching to the maximum the bank will lend
Just because a bank will lend you 4.5× your salary doesn't mean you should borrow that much. Leave buffer for rate rises, life changes, and maintenance costs.
Ignoring the 10% overpayment allowance
If you have spare cash, overpaying is almost certainly a better return than savings accounts, especially at current mortgage rates. Even £50/month makes a meaningful difference over 25 years.
Not getting a survey on an older property
A HomeBuyer Report (£400) or Building Survey (£600) can uncover structural issues worth tens of thousands in repairs. Never skip the survey to save a few hundred pounds.
Choosing a 35-year term to make payments 'affordable'
A longer term means lower monthly payments but dramatically more total interest. A £250,000 mortgage at 4.5%: 25 years costs £167k in interest; 35 years costs £231k. That's £64,000 extra.
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Sources
- Bank of England, base rate and mortgage market data
- FCA, Mortgage Conduct of Business rules (MCOB)
- MoneyHelper (formerly Money Advice Service), mortgage guidance
- UK Finance, mortgage lending statistics and trends
- ONS, UK House Price Index (average property prices)
- HMRC, Stamp Duty Land Tax thresholds and rates
How to use this tool
Enter the property price, deposit amount, interest rate, and mortgage term
Choose between repayment and interest-only, and optionally add monthly overpayments
View your monthly payment, total interest, LTV ratio, and year-by-year schedule
Common uses
- Working out monthly mortgage payments before buying
- Comparing different mortgage rates and terms
- Calculating the impact of overpayments on interest savings
- Checking loan-to-value ratio for rate band assessment
- Planning deposit savings targets
- Comparing repayment vs interest-only costs
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