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Mortgage Repayment Planner

Mortgage Overpayment Calculator

See how extra monthly payments, annual overpayments, or a one-time lump sum could shorten your mortgage and reduce interest.

Instant comparisonEstimated payoff datesInterest savings

Enter your mortgage details

Use your current balance, rate, and remaining term—not the original loan figures.

Your overpayment plan
Applied at the end of every 12 months.
Enter 0 if your lender has no stated limit.

How the mortgage overpayment calculator works

The calculator first estimates the principal-and-interest payment required to repay your current balance over the remaining term. It then builds a second month-by-month schedule that applies your chosen overpayments directly to principal. The difference between the schedules shows the estimated interest and time saved.

1. Add current figures

Enter the balance, annual rate, and time remaining on your mortgage.

2. Choose overpayments

Test a recurring monthly amount, annual payment, lump sum, or a combination.

3. Compare outcomes

Review the new payoff date, interest saved, and reduction in repayment time.

Why mortgage overpayments can make a difference

Lower interest cost

Reducing principal sooner means less balance remains for future interest charges.

Earlier payoff

Regular extra payments may remove months or years from the remaining term.

Flexible planning

Compare small recurring amounts with occasional larger payments before committing.

Before overpaying: confirm that your lender applies extra money to principal, check any annual allowance or prepayment penalty, and keep enough accessible savings for emergencies.

Frequently asked questions

Does a mortgage overpayment reduce principal?

It usually does when the lender applies the extra amount as a principal payment. Ask the lender how to label or submit overpayments so they are not treated as future scheduled payments.

Is it better to overpay monthly or make a lump sum?

Paying earlier generally reduces interest sooner, so monthly overpayments can have an advantage. However, the best choice depends on cash flow, lender rules, and whether your money has a more valuable alternative use.

Can I overpay a fixed-rate mortgage?

Many fixed-rate mortgages permit limited annual overpayments, but terms vary. Review your agreement for allowances, early repayment charges, and excluded payment types.

Does the calculator include taxes and insurance?

No. It calculates mortgage principal and interest only. Property taxes, homeowners insurance, association fees, and mortgage insurance do not reduce the loan balance.

Are these results guaranteed?

No. Results are planning estimates. Actual savings depend on payment timing, lender calculations, rate changes, fees, and how extra payments are processed.