UK Mortgage Repayment Calculator

Calculate monthly payments, total interest and full mortgage cost — residential, BTL, let-to-buy & right-to-buy

✓ Repayment & interest-only ✓ Buy-to-let & let-to-buy ✓ Stress test at +3% ✓ Free — no signup
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Mortgage Details
Mortgage Purpose
Buyer Type
Buy-to-Let: Minimum 25% deposit typically required. Most BTL mortgages are interest-only. Rental income must cover 125–145% of monthly payments.
Let-to-Buy: You’ll switch your current mortgage to a let-to-buy arrangement and take a new residential mortgage on the property you’re moving to.
Right-to-Buy: Council tenants can buy at a discount of up to £96,000 (£127,900 in London). Enter the discounted price below.
£
£
Mortgage Amount £280,000
LTV 80.0%
Deposit % 20.0%
%

Enter your details and click Calculate Repayments to see your monthly payment, total interest, amortisation schedule and stress test result.

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Your Results
Monthly Payment
£0
Repayment mortgage
Mortgage amount £0
Loan to value (LTV) 0%
Monthly payment £0
Total repaid £0
Total interest £0
Interest as % of loan 0%
Stamp duty on this property View estimate →
Year-by-Year Amortisation
Year Payment Interest Capital Balance
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Stress Test — Rate +3%
At a rate of X.X%, your monthly payment would be:
£0

For guidance only. Always verify mortgage costs with a qualified mortgage adviser. Rates, fees and eligibility will vary.

Important Information

⚠️ Rates change — get a broker quote. This calculator uses a fixed rate. Your actual mortgage rate will depend on your LTV, credit score, and lender. Always get a personalised quote from a broker or lender before committing.
⚠️ Stress test — Can you afford +3%? Lenders are required to check you can afford repayments if rates rise by up to 3%. Our stress test shows your payment at that level. Make sure you have sufficient headroom in your budget before proceeding.
⚠️ Arrangement fees add to cost. Many mortgage deals charge arrangement fees of £999–£1,999. Adding these to the mortgage means you pay interest on them over the full term, increasing your total cost significantly.

Mortgage Reliefs & Government Schemes

Depending on your circumstances, you may be eligible for government-backed schemes or tax reliefs that reduce your mortgage costs.

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First Homes Scheme

First-time buyers can get 30–50% off the market price on selected new-build homes in England. Discount is locked to the property for future sales.

Learn more on GOV.UK →
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Right to Buy

Council tenants in England can buy their home at a discount of up to £96,000 (£127,900 in London), depending on how long they’ve been a tenant.

Check eligibility on GOV.UK →
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Lifetime ISA (LISA)

Save up to £4,000/year and get a 25% government bonus (up to £1,000/year) towards your first home deposit. Must be aged 18–39 to open.

Learn more on GOV.UK →
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Mortgage Interest Tax Relief (BTL)

Landlords can claim a 20% tax credit on mortgage interest payments against rental income. The old full deduction was replaced in April 2020.

Learn more on GOV.UK →
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Shared Ownership

Buy a share (25–75%) and pay rent on the rest. Available through housing associations. You can staircase up to full ownership over time.

Learn more on GOV.UK →
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Stamp Duty FTB Relief

First-time buyers pay 0% SDLT on the first £300,000 and 5% on £300,001–£500,000. Above £500,000, standard rates apply.

Calculate your FTB stamp duty →

Worked Examples

See how different mortgage types, deposits and rates affect your monthly payment and total cost.

First Time Buyer — Repayment

Property price £300,000
Deposit (10%) £30,000
Mortgage £270,000
Term / Rate 25 yrs @ 4.5%
Stamp duty (FTB relief) £0
Monthly Payment
£1,501
Total interest £180,415

Buy-to-Let — Interest Only

Property price £250,000
Deposit (25%) £62,500
Mortgage £187,500
Term / Rate 25 yrs @ 5.5%
Stamp duty (+3% surcharge) £10,000
Monthly Payment
£859
Min. rental needed (125%) £1,074/mo
Balance owed at end £187,500

Home Mover — Repayment

Property price £500,000
Deposit (20%) £100,000
Mortgage £400,000
Term / Rate 25 yrs @ 4.0%
Stamp duty £12,500
Monthly Payment
£2,111
Total interest £233,400

Right-to-Buy — Repayment

Market value £200,000
RTB discount −£80,000
Purchase price £120,000
Deposit (5%) £6,000
Mortgage £114,000
Term / Rate 25 yrs @ 5.0%
Monthly Payment
£667
Total interest £85,950

Not sure which mortgage is right for you?

A whole-of-market mortgage broker compares deals from every UK lender — not just the ones on the high street. They handle the paperwork, negotiate rates, and guide you through the application process. Many charge no upfront fee (they are paid by the lender on completion).

This is general guidance, not a recommendation. Always compare your options. Your home may be repossessed if you do not keep up repayments on your mortgage.

Frequently Asked Questions

Everything you need to know about mortgage repayments, interest rates, and buying costs in the UK.

A repayment mortgage uses an amortisation formula: monthly payment = P × [r(1+r)n] / [(1+r)n − 1], where P is the loan amount, r is the monthly interest rate (annual rate ÷ 12), and n is the total number of monthly payments (years × 12). Each payment covers the interest accrued that month plus a portion of the capital, so the balance reduces to zero at the end of the term.
With a repayment mortgage, each monthly payment covers the interest charged plus a portion of the original loan (capital), so the debt reduces over time and is fully repaid at the end of the term. With an interest-only mortgage, you only pay the interest each month; the full original loan remains outstanding and must be repaid separately at the end — usually through savings, investments, or selling the property.
A buy-to-let (BTL) mortgage is designed for properties you intend to rent out. BTL mortgages typically require a minimum 25% deposit, have higher interest rates than residential mortgages, and are often interest-only. Lenders assess affordability based on expected rental income (usually 125–145% of monthly payments) rather than your personal salary.
A let-to-buy mortgage allows you to rent out your current home while buying a new one. You switch your existing residential mortgage to a let-to-buy (or consent-to-let) arrangement, then take out a new residential mortgage on the property you are moving to. This is common when relocating or unable to sell your current home.
Loan-to-value (LTV) is the mortgage amount as a percentage of the property value. The lower your LTV, the less risk the lender takes, so they typically offer lower interest rates. LTV bands of 60%, 75%, 80%, 85%, 90%, and 95% are common thresholds — rates rise noticeably above 75% LTV. A larger deposit secures a lower LTV and usually a better rate.
A mortgage stress test checks whether you could still afford your repayments if interest rates rose by up to 3 percentage points above your initial rate. UK lenders are required to carry out affordability assessments that include a stress test. Our calculator shows what your monthly payment would be at your rate plus 3%, helping you judge whether your budget has enough headroom.
The minimum deposit for a standard residential mortgage in the UK is usually 5% of the property price (95% LTV). However, rates improve significantly at 10%, 15%, and 25% deposits. First-time buyers may access government schemes with a 5% deposit. Buy-to-let mortgages typically require a minimum 25% deposit. A larger deposit means lower monthly payments and access to better rates.
Right to Buy allows most council tenants in England to buy their council home at a discount. The discount can be up to £96,000 (£127,900 in London) depending on how long you have been a tenant. You need a mortgage for the remaining amount after the discount. Not all lenders offer Right to Buy mortgages, but specialist brokers can help you find one. Source: gov.uk/right-to-buy
Yes. Most UK mortgage deals allow overpayments of up to 10% of the outstanding balance per year without penalty. Overpaying reduces your outstanding balance faster, cuts the total interest you pay, and can shorten your mortgage term. Always check your lender’s terms — exceeding the overpayment limit can trigger early repayment charges (ERCs), particularly on fixed-rate deals.
Arrangement fees (also called product fees) are charged by lenders to set up a mortgage. They typically range from £999 to £1,999, though some deals have no fee but a higher interest rate. You can pay the fee upfront or add it to your mortgage — adding it means you pay interest on the fee over the full term, increasing your total cost. Always compare the total cost over the deal period, not just the headline rate.
A longer mortgage term (e.g. 35 years vs 25 years) lowers your monthly payments but significantly increases the total interest you pay over the life of the loan. A shorter term means higher monthly payments but you own your home outright sooner and pay far less interest overall. Most UK mortgages are taken over 25 years, but many first-time buyers now choose 30–35 years to keep monthly costs manageable.
A fixed-rate mortgage locks your interest rate for a set period (typically 2, 3, or 5 years), giving predictable monthly payments regardless of Bank of England base rate changes. A tracker mortgage has a rate that moves in line with the base rate (e.g. base rate + 1%), so payments rise and fall with market rates. Fixed rates offer certainty; trackers can be cheaper when rates fall but carry the risk of rising payments.
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First-Time Buyer Mortgage

FTB mortgage with stamp duty relief and affordability check

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Buy-to-Let Calculator

BTL mortgage with rental yield, ICR and Section 24 tax

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Remortgage Calculator

Compare current vs new deal with fee payback analysis

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Stamp Duty Calculator

Calculate your SDLT including BTL surcharge and FTB relief

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Income Tax Calculator

Calculate your 2026/27 income tax and take-home pay

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Pension Tax Relief

See how much tax relief you get on pension contributions

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