Property Tools
Mortgage Cost Comparison UK
Designed by mortgage advisors · Built for the mortgage industry
Compare mortgage deals on their true cost — including payments over the deal term, product fees, valuation, legal costs, and remaining balance. See whether adding a fee to the mortgage actually costs you more.
Deal A
Deal B
How the Comparison Works
Monthly Repayment Formula
P = mortgage balance
r = monthly interest rate (annual ÷ 12 ÷ 100)
n = full term in months
The standard UK capital repayment formula. If the product fee is added to the mortgage, P increases accordingly, raising both the monthly payment and total interest.
Remaining Balance Formula
k = deal term in months
B(k) = outstanding balance at end of deal
The remaining balance matters at remortgage — a lower balance improves your loan-to-value ratio and may qualify you for better rates on your next deal.
Total Cost of Deal
Upfront Fees = product fee (if not on balance)
+ valuation + legal + other fees
This is the true cash outflow during the deal period. It is the primary figure mortgage advisors use to determine which deal is genuinely cheaper for a client.
Fee to Mortgage vs. Pay Upfront
→ Higher M, more interest paid
Paid upfront → P unchanged
→ Lower M, fee added directly to total cost
Adding a fee to the mortgage typically costs more over the term due to compounding interest, but avoids an upfront cash requirement. This calculator shows both scenarios clearly.
The Calculator App Editorial Team · 25+ Years UK Financial Services
Important Information
This calculator is for illustrative purposes only and does not constitute mortgage advice, a personal recommendation, or a mortgage offer.
Results are based on the figures you enter and assume a standard capital repayment structure. Actual rates, fees, terms, and eligibility will vary by lender and individual circumstances.
You should seek independent advice from a qualified mortgage adviser or broker before making any financial commitment.