Should you be making extra mortgage payments?
What if you have extra cash and want to use it to pay down your principal?
This calculator can help you decide. Enter in the details of your mortgage and how much you want to pay today, it will calculate how much that extra payment will save you over the remainder of your mortgage.
As a comparison, it will also show you how much that amount will grow to if you invested it instead. We include a conservative rate of return.
You can save your numbers by clicking “Save to browser” or Copy link, which can be sent to anyone and saves nothing to your computer. It saves the values as arguments in the link.
Mortgage extra payment savings
See what one small extra payment saves you over the life of your loan.
For reference, the S&P 500 has averaged roughly 10.1% annually over the last 30 years (1996–2025) with dividends reinvested. 8% is a more conservative long-term assumption. Source: Fidelity
Estimate assumes the extra payment is applied to principal and your monthly P&I stays the same.
See year-by-year amortization comparison
| Year | Without extra | With extra | ||
|---|---|---|---|---|
| Balance | Interest | Balance | Interest | |
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