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🔑 Mortgage Overpayment Calculator

A mortgage overpayment calculator shows how much interest you save and how many years you shave off your mortgage by making extra monthly payments. Compare your standard repayment schedule versus an overpayment strategy to see the exact interest saved and years gained.

🇺🇸 Calculating for United States
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Mortgage details

Interest saved by overpaying £200.00/month

£38,457.87

Compared with paying £1,389.58/month over the full 25-year term

Months saved

61 months

New payoff date

Jun 2046

Total interest with overpayments

£128,416.49

Overpayment savings

You save £38,457.87 in interest and pay off 61 months early — clearing the mortgage by Jun 2046 instead of after the full 25-year term.

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Frequently asked questions

How much can I save by overpaying my mortgage?
Even small monthly overpayments reduce interest dramatically due to compounding in reverse. A £500 overpayment on a £250,000 25-year mortgage at 4.5% can save £25,000+ in interest and cut 4–5 years off the term.
Is there a limit on mortgage overpayments in the UK?
Most UK mortgage lenders allow overpayments of up to 10% of the outstanding balance per year without an early repayment charge (ERC). Always check your mortgage terms before overpaying to avoid penalties.
Should I overpay my mortgage or invest instead?
Compare your mortgage rate to expected investment returns after tax. With UK mortgages at 4–6% and ISA/equity returns potentially 5–10%+, investing often wins mathematically — but overpaying offers guaranteed, risk-free "return" equal to your rate.
What happens when I overpay a UK mortgage?
Overpayments reduce your outstanding balance, which lowers the interest charged each month. Your lender may let you reduce your monthly payment or keep it the same and shorten the term — the latter saves more interest overall.

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Disclaimer: This calculator is for informational and educational purposes only. Results are estimates and not financial advice. Consult a licensed financial advisor before making financial decisions.