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UK Mortgage Calculator with Stamp Duty

Calculate UK mortgage monthly payments, total interest, and stamp duty land tax. Supports repayment and interest-only mortgages with UK-specific tax rates.

Formula

Repayment mortgage calculation

Calculates monthly repayments using standard amortization and estimates Stamp Duty Land Tax based on current England/NI rates.

Worked Examples

Example 1: Calculate UK Mortgage Payment

Problem:£350,000 property, £70,000 deposit (20%), 5.5% rate, 25 years.

Solution:Mortgage amount: £350,000 - £70,000 = £280,000\nLTV: 80%\n\nMonthly payment calculation:\nr = 5.5% ÷ 12 = 0.458%\nn = 25 × 12 = 300 months\n\nPayment = £280,000 × [0.00458(1.00458)^300] / [(1.00458)^300-1]\nPayment = £1,716/month\n\nTotal repaid: £514,800\nTotal interest: £234,800

Result:£1,716/month | £234,800 interest

Example 2: Stamp Duty Calculation

Problem:Buying £500,000 property (not first-time buyer).

Solution:Stamp Duty bands:\n£0 - £250,000: 0% = £0\n£250,001 - £500,000: 5% = £12,500\n\nTotal Stamp Duty: £12,500\n\nIf first-time buyer:\n£0 - £425,000: 0%\n£425,001 - £500,000: 5% = £3,750\nFirst-time buyer saves: £8,750

Result:£12,500 (or £3,750 for FTB)

Example 3: LTV Impact on Rates

Problem:£300,000 property. Compare 10% vs 25% deposit.

Solution:10% deposit (90% LTV):\nMortgage: £270,000\nTypical rate: 5.8%\nPayment: £1,706/month\n\n25% deposit (75% LTV):\nMortgage: £225,000\nTypical rate: 5.2%\nPayment: £1,339/month\n\nMonthly savings: £367\nBetter rate + smaller loan = significant savings

Result:25% deposit saves £367/month

Frequently Asked Questions

What is stamp duty in the UK?

Stamp Duty Land Tax (SDLT) is a tax on property purchases in England and Northern Ireland. Current rates: 0% up to £250,000, 5% on £250,001-£925,000, 10% on £925,001-£1,500,000, 12% above £1.5M. First-time buyers get relief up to £425,000.

What is a fixed vs variable rate mortgage?

Fixed: rate locked for 2-5 years, payments predictable. Variable/tracker: follows Bank of England base rate, can go up or down. Standard Variable Rate (SVR): lender's default rate, usually higher - avoid staying on SVR.

What are mortgage fees in the UK?

Common fees: Arrangement fee (£0-2,000), valuation fee (£150-1,500), legal fees (£850-1,500), survey (£250-600). Some lenders offer fee-free mortgages with slightly higher rates. Compare total cost, not just rate.

Can I get a mortgage as a first-time buyer?

Yes, various schemes help: Lifetime ISA (25% government bonus), Help to Buy equity loan, shared ownership, First Homes scheme (30% discount). Stamp duty relief on first £425,000. Many 95% LTV products available.

References