Mortgage Calculator

Calculate monthly mortgage repayments, total interest and stamp duty. Based on UK rates and regulations for 2024/2025.

Lenders typically lend 4.5× household income

Monthly Payments

Rate: 5.5% | Term: 25 years
Monthly Repayment £0.00 Principal + Interest
Total Over Term £0.00 All repayments combined
Total Interest £0.00 Cost of borrowing

Stamp Duty Land Tax (SDLT)

Stamp Duty Due £0.00 Standard rate
First-Time Buyer Relief £0.00 If applicable
Total Purchase Cost £0.00 Price + SDLT

Calculation Breakdown

1 £250,000 Property Price
2 £50,000 Deposit
3 £200,000 Loan Amount
4 £1,XXXX/mo Monthly Payment

Interest Impact by Term Length

15yr
£X,XXX
20yr
£X,XXX
25yr
£X,XXX
30yr
£X,XXX

Longer terms = lower monthly payments but higher total interest

Summary

For a £250,000 property with a £50,000 deposit (20%), your monthly mortgage payment would be approximately £1,XXX/month over 25 years at 5.5% interest. Total interest paid: £XX,XXX. Stamp duty: £X,XXX.

How Mortgage Calculations Work

Mortgage repayments are calculated using an amortisation formula that spreads your loan plus interest evenly across your term. The formula accounts for compound interest: Monthly Payment = [P × r × (1+r)^n] / [(1+r)^n − 1] where P = principal, r = monthly interest rate, n = total months.

Stamp Duty Land Tax (SDLT) 2024/2025

Property Price Standard Rate First-Time Buyers
Up to £250,000 0% 0%
£250,001 – £925,000 5% 0% (up to £425,000)
£925,001 – £1.5M 10% 5% (£425,001-£625,000)
Over £1.5M 12% 12% (over £625,000)

First-time buyer relief was extended to September 2025. Additional properties incur a 3% surcharge.

Deposit Requirements

  • 5% deposit (95% LTV): Highest interest rates, stricter eligibility
  • 10-15% deposit (85-90% LTV): Better rates, wider product choice
  • 20% deposit (80% LTV): Competitive rates, most mortgage options
  • 25%+ deposit (75% LTV or less): Best interest rates available

The larger your deposit, the lower your Loan-to-Value ratio and the better interest rates you can access.

Mortgage Term Length

Typical mortgage terms range from 15-40 years. Shorter terms mean higher monthly payments but significantly less total interest. Longer terms reduce monthly负担 but can add tens of thousands in extra interest over the life of the loan.

Example: On a £200,000 mortgage at 5.5%:

  • 15 years: £1,639/month, £95,000 total interest
  • 25 years: £1,229/month, £168,700 total interest
  • 30 years: £1,132/month, £207,500 total interest

Affordability Checks

Lenders typically offer mortgages of 4.5× your annual household income. Some may go up to 5× for high earners or those with exceptional credit scores. Your debt-to-income ratio, existing commitments (loans, childcare), and credit history also affect approval.

Important Disclaimer

This calculator provides estimates only. Your actual mortgage rate, monthly payment, and terms will depend on:

  • Individual lender policies and criteria
  • Your credit score and financial history
  • Current market conditions and base rates
  • Property type and valuation
  • Your employment status and income stability
  • Additional fees (arrangement, legal, valuation)

Always speak with a qualified mortgage advisor for personalised advice. This calculator is not financial advice.

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