UK Mortgage Calculator

Estimate monthly repayments and total interest for a repayment or interest-only mortgage, with a full amortisation schedule.

25 years30 years20 years15 years
RepaymentInterest-only
Monthly
£1,491
Monthly payment
Loan amount
£255,000
Loan-to-value (LTV)
85%
Total interest
£192,211
Principal £255,000Interest £192,211

Loan balance over time

Remaining balance at the end of each year (repayment mortgage).

Amortisation schedule

Expand all

Yearly summary — click a row to see monthly detail.

YearPaidPrincipalInterestBalance
Year 1£17,888£5,258£12,631£249,742
Year 2£17,888£5,527£12,362£244,215
Year 3£17,888£5,810£12,079£238,406
Year 4£17,888£6,107£11,782£232,299
Year 5£17,888£6,419£11,469£225,879
Year 6£17,888£6,748£11,141£219,132
Year 7£17,888£7,093£10,796£212,039
Year 8£17,888£7,456£10,433£204,583
Year 9£17,888£7,837£10,051£196,746
Year 10£17,888£8,238£9,650£188,507
Year 11£17,888£8,660£9,229£179,848
Year 12£17,888£9,103£8,786£170,745
Year 13£17,888£9,569£8,320£161,176
Year 14£17,888£10,058£7,830£151,118
Year 15£17,888£10,573£7,316£140,546
Year 16£17,888£11,114£6,775£129,432
Year 17£17,888£11,682£6,206£117,750
Year 18£17,888£12,280£5,609£105,470
Year 19£17,888£12,908£4,980£92,562
Year 20£17,888£13,568£4,320£78,993
Year 21£17,888£14,263£3,626£64,731
Year 22£17,888£14,992£2,896£49,738
Year 23£17,888£15,759£2,129£33,979
Year 24£17,888£16,566£1,323£17,413
Year 25£17,888£17,413£475£0
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How to use this UK mortgage calculator

Enter the property price, your deposit, the interest rate and the term, then choose repayment or interest-only. The calculator shows your monthly payment, total interest, loan-to-value, a balance chart and a full amortisation schedule — all updating instantly.

Stamp Duty (SDLT) — a separate upfront cost

On top of your mortgage, buying a home in England or Northern Ireland may attract Stamp Duty Land Tax. From April 2025 the standard residential thresholds are:

Portion of priceSDLT rate
Up to £125,0000%
£125,001 – £250,0002%
£250,001 – £925,0005%
£925,001 – £1.5m10%
Over £1.5m12%

First-time buyers pay no SDLT up to £300,000. Wales (LTT) and Scotland (LBTT) have their own equivalents. Stamp Duty is not included in the monthly figures above.

Estimates use standard formulas. Your actual rate, fees and Stamp Duty will vary — confirm with your lender or a mortgage adviser.

Frequently Asked Questions

What is the difference between repayment and interest-only?
On a repayment (capital & interest) mortgage each payment clears some interest and some of the loan, so the balance reaches zero by the end of the term. On interest-only you pay just the interest each month and still owe the full amount at the end, which you must repay separately.
How is the monthly repayment calculated?
A repayment mortgage uses the standard amortisation formula: M = P × r × (1+r)ⁿ ÷ [(1+r)ⁿ − 1], where r is the monthly interest rate and n is the number of months. Interest-only is simply the balance multiplied by the monthly rate.
What is loan-to-value (LTV)?
LTV is the loan as a percentage of the property value. A bigger deposit means a lower LTV, which usually unlocks better mortgage rates. For example, a £30,000 deposit on a £300,000 home is a 90% LTV.
Does this include Stamp Duty?
No. This calculator focuses on monthly repayments and interest. Stamp Duty Land Tax (SDLT) is a separate upfront cost when you buy — see the notes below for current thresholds.
Will my rate stay the same?
Most UK mortgages are fixed for an initial period (commonly 2 or 5 years) and then move to the lender’s variable rate. This tool assumes a single rate for the whole term, so re-run it when your deal changes.

📅 Last updated: June 2026 · Formulas follow standard banking / tax conventions · Results are for reference only.