Mortgage Repayment Calculator
Loan details
Fill in the fields above to see your result instantly.
How it works
This is the standard amortising mortgage formula. Each monthly payment is split between interest (charged on the remaining balance) and principal (reducing the balance). Early payments are mostly interest; later payments are mostly principal.
Worked example
£200,000 loan, 4.5% rate, 25 years: monthly payment £1,112, total paid £333,524, total interest £133,524. Same loan over 30 years: £1,013/month but £164,813 total interest.
Who should use this
- •Buyers comparing 25 vs 30 vs 35 year terms
- •Anyone modelling rate-rise scenarios
- •Homeowners checking overpayment impact
Common mistakes
- ×Picking the longest term to lower monthly payment without understanding total interest cost
- ×Ignoring product fees (often £999) which add to true cost
- ×Forgetting buildings insurance and life cover are mandatory
- ×Not stress-testing at +2% in case rates rise at remortgage
Frequently asked questions
Should I overpay my mortgage?▾
Most lenders allow 10%/year overpayments penalty-free. Even £100/month extra can save tens of thousands and shave years off the term.
Is interest-only cheaper?▾
Monthly payments are lower but you owe the full capital at the end. Used mainly for buy-to-let now.
What is APRC?▾
Annual Percentage Rate of Charge — includes the rate plus fees over the whole term, not just the fixed period.