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What does an extra $100 a month do to your mortgage?

On a $350,000 mortgage at 6.5% over 30 years, adding $100 a month saves roughly $62,627 in interest and 3 yr 6 mo. Run your own numbers below.

Your extra-$100 plan

Amortization schedule
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Estimates only, not a loan offer. Excludes taxes, insurance and fees unless entered. See our disclaimer.

A small habit, a five-figure result

The calculator above is pre-set with an extra $100 a month on a sample $350,000 loan at 6.5%. The standard payment is about $2,212.24; adding $100 takes roughly 3 yr 6 mo off the loan and saves about $62,627 in interest. Change the amount, rate, or balance to match your own mortgage.

Why does so little do so much? Because the extra $100 goes entirely to principal. That shrinks the balance interest is charged on, so every future payment chips away faster — the savings compound over the life of the loan.

Want to go bigger?

See what larger amounts do: an extra $300 a month or an extra $500 a month. Or aim for a target date with the pay-off-in-15-years calculator.

Make sure your servicer applies the extra to principal. Download your plan as Excel or PDF to keep a record.

Frequently asked questions

How much does paying an extra $100 a month save on a mortgage?
On a $350,000 mortgage at 6.5% over 30 years, paying an extra $100 a month saves about $62,627 in interest and pays the loan off roughly 3 yr 6 mo early. Your own numbers depend on your balance and rate — set them above.
Is $100 extra a month worth it?
For a small, painless amount, the long-run effect is large because every extra dollar goes straight to principal and stops accruing interest for the rest of the loan. It is one of the lowest-effort ways to save five figures over time.
Should I pay $100 extra or invest it?
Paying extra is a guaranteed return equal to your mortgage rate; investing may earn more but carries risk. Many people do some of each. Compare your rate to expected after-tax investment returns before deciding.