Mortgage calculator
What this mortgage calculator does
- Monthly repayments based on loan size, interest rate, and term
- How much of each payment goes to interest vs principal (repayment only)
- Loan-to-value (LTV) ratio
- Effect of adding fees to the mortgage
Important: results are estimates for guidance only. Get personalised advice from a qualified mortgage advisor before making decisions.
How the mortgage calculation works
Loan amount
Property value minus deposit, optionally plus fees if you tick “include in mortgage”.
Interest rate
Annual percentage rate (APR), converted to a monthly rate for calculations.
Repayment mortgage
Uses the standard mortgage formula:
- Monthly rate = Annual rate ÷ 12
- Number of payments = Years × 12 + months
- Payment calculated using compound interest formula
Interest-only mortgage
Monthly payment = Loan amount × monthly interest rate
Note: capital is not repaid during the term. A repayment strategy will be required to clear the balance at the end.
Assumptions
- Fixed interest rate throughout the term
- Payments made monthly and on time
- No overpayments, fee changes, or rate changes
Tips to reduce your monthly mortgage payment
- Increase your deposit: reduce LTV for better rates and lower payments
- Choose a longer term: lower monthly payments (but higher total interest)
- Compare products: fixed vs tracker rates for competitive deals
- Consider fees: balance product fees vs interest rate trade-offs
Frequently asked questions
What is LTV?
Loan-to-value is the percentage of the property’s value you are borrowing. For example, a £200,000 property with a £40,000 deposit is 80% LTV.
Repayment vs interest-only?
Repayment reduces your balance each month. Interest-only means you only pay interest and must repay the capital at the end with savings, investments, or other funds.
Can I include fees in the mortgage?
Yes, you can choose to add fees to the loan. This increases the loan amount and the total interest paid.
Why is my payment different from other calculators?
Different tools use different rounding or assumptions. Lender products and fees vary. Treat this as a guide.
UK-specific guidance
Stamp Duty
Depending on property value and buyer status (first-time buyer, additional property), Stamp Duty Land Tax may apply.
Affordability
Lenders assess income, outgoings, credit history, and other commitments.
Protection
Consider insurance (life, income protection, buildings insurance) as part of mortgage planning.
Important notes and limitations
- Results are estimates, not quotes
- Real offers depend on your credit profile, affordability, lender criteria, and product specifics
- If interest rates change, your payments will differ
- Interest-only requires a credible repayment plan for the capital
For tailored advice, consider speaking with a qualified mortgage advisor.
Our advisors are here to help
Our CeMAP-qualified advisers guide you every step of the way, providing expert mortgage advice from consultation to completion.
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