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Mortgages & Property · 2025 rates

UK Mortgage Repayment Calculator

See your monthly payment, the total interest you’ll pay, and how the balance shrinks year by year. Plus a quick affordability check based on UK lenders’ income multiples.

Your mortgage

£
£

90.0% loan-to-value (LTV)

%
yrs

Assumes a standard capital-and-interest repayment mortgage at a fixed rate. Real deals change rate after the fixed period.

Monthly payment
£1,500.75
Loan
£270,000
Total interest
£180,224
Total repaid
£450,224
LTV: 90.0% · Term: 25 years

What you’re paying for

  • Property price
    £300,000
  • Deposit
    What you put down up front
    £30,000
  • Loan from lender
    £270,000
  • Total interest over term
    Spread across 300 monthly payments
    −£180,224
  • Total cost of borrowing
    £450,224

Balance over time (every 5 years)

YearInterest paidCapital paidBalance left
Year 5£10,850£7,159£237,216
Year 10£9,048£8,961£196,178
Year 15£6,792£11,217£144,806
Year 20£3,967£14,042£80,499
Year 25£431£17,578£0

How much could a lender offer you?

Quick estimate based on UK lenders’ typical income multiples (4–5× combined salary).

£
£
Cautious (4×)
£180,000
Typical (4.5×)
£202,500
Generous (5×)
£225,000

Lenders also stress-test your monthly outgoings against the payment. A clean credit file and low existing debt push you toward the higher end; childcare, loans, or thin credit history push you down.

How we calculated your result

A repayment mortgage is calculated with the standard amortisation formula:

M = P · r(1+r)ⁿ / ((1+r)ⁿ − 1)

Where P is your loan, r is the monthly interest rate (annual ÷ 12), and n is the number of months (term × 12).

The monthly payment is constant, but each payment is split between interest (on the remaining balance) and capital. Early on, most of the payment is interest; later, most of it is capital. That’s why overpaying in year 1 saves you so much more than overpaying in year 20.

The affordability estimate uses the standard UK lender rule of thumb: 4.5× combined gross salary is the typical maximum, with 4× being cautious and 5× being generous (and reserved for higher earners with clean credit files).

Official UK rules in simple English

The UK mortgage market has a few hard rules and a lot of lender-specific ones. The ones that matter most:

  • Loan-to-value (LTV) = loan ÷ property price. Most lenders cap at 95% LTV for residential mortgages. Better rates appear at 90%, 85%, 75% and 60% LTV bands.
  • Income multiples: lenders typically lend up to 4.5× combined salary, sometimes 5–5.5× for high earners or specific schemes. The FCA’s Mortgage Market Review caps the proportion of loans any lender can issue above 4.5×.
  • Affordability stress tests: lenders model whether you could still afford the payment if rates rose by ~1–3%. This often constrains how much you can borrow more than the income multiple does.
  • Term: standard maximum is 35 years (some lenders go to 40). Longer term = smaller monthly payment but much more total interest.

Common pitfalls to watch out for

  • ⚠ The headline rate is rarely what you pay long-term

    Most UK mortgages are fixed for 2, 5 or 10 years, then revert to the lender’s Standard Variable Rate — usually 3–5% higher. Plan to remortgage at the end of your fix, or budget for a much higher payment.

  • ⚠ A longer term saves monthly but costs a fortune total

    Pushing a £200k loan at 5% from a 25-year term to a 35-year term cuts the monthly payment by about £160 — but adds nearly £45,000 to the total interest. Use the shortest term you can comfortably afford.

  • ⚠ Don’t forget the upfront costs

    On top of your deposit, budget for: Stamp Duty (use our SDLT calculator), legal fees (£1,000–£2,000), survey (£300–£1,500), mortgage product/arrangement fee (£0–£2,000), and removals. Easily £3,000–£8,000 on a typical purchase.

  • ⚠ Affordability ≠ maximum loan

    Just because a lender will offer you 4.5× salary doesn’t mean you should take it. Stress-test yourself against the actual monthly payment — including a 2% rate rise — and don’t forget childcare, pension contributions, and the cost of running the house itself.

Frequently asked questions

Should I overpay or invest?
Rule of thumb: if your mortgage rate is higher than the return you’d realistically get from an ISA after tax, overpay. At 5%+ mortgage rates, overpaying usually beats investing. Check your lender’s overpayment limit first — typically 10% of the balance per year without an early repayment charge.
Is interest-only cheaper?
Each month, yes — you only pay the interest. But you still owe the full loan at the end of the term and need a repayment vehicle (ISA, investments, sale of property) to clear it. UK lenders rarely offer interest-only for residential anymore; it’s mostly a buy-to-let product now.
What is a tracker mortgage?
A tracker mortgage moves with the Bank of England base rate, usually base + a fixed margin (e.g. base + 0.5%). You benefit when rates fall and pay more when they rise. Fixes give certainty; trackers give optionality.

Figures are an estimate. The exact monthly payment your lender quotes will depend on the product fee, any cashback, and how interest is calculated (daily vs monthly). Always check the lender’s Key Facts Illustration.

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