Your mortgage details
See how extra payments change everything
🏠 Your mortgage
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yr
➕ Extra payment
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Even $100/month makes a dramatic difference on a 30-year mortgage.
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Extra payment calculator
Enter your current mortgage and an extra monthly payment. See the exact interest saved, years cut off your loan, and whether the math makes sense.
Total interest saved
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Time saved
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Standard total interest
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With extra payments
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Extra payment questions, answered
How much does an extra $100/month save on a mortgage?
On a $300,000 mortgage at 6.72% with 25 years remaining: an extra $100/month saves approximately $31,000 in total interest and cuts 2.5 years off your loan.
Should I make extra payments or invest the money?
This depends on your interest rate vs. expected investment returns. If your mortgage rate is 6.72%, you'd need to consistently earn more than 6.72% after tax to beat paying down the mortgage.
Why do extra payments save so much more in early years?
Because interest is calculated on your remaining balance. Extra payments in early years reduce the balance sooner, cutting the interest charged every month after that.
Is it better to make one lump sum or monthly extras?
A lump sum applied immediately saves slightly more because it reduces the balance right away. Monthly extras are easier to budget. Both are dramatically better than standard payments.
Do all lenders allow extra payments without penalty?
Most conventional mortgages allow extra payments without penalty. However, some loans — especially subprime or older mortgages — have prepayment penalties. Check your loan agreement.