How the Extra Mortgage Payment Calculator works
See how extra payments may reduce interest and payoff time. Adjust the inputs above, then use the calculate button to generate a fresh estimate based on the numbers you entered.
The result is designed to give you a quick planning number, plus a short breakdown of the major figures behind it. You can reset the form at any time and try a different scenario.
When to use this calculator
Use this extra mortgage payment calculator to estimate how a recurring extra payment may reduce your payoff time and total interest. It is helpful when deciding whether to add a little more each month, increase payment frequency or use extra cash toward the mortgage.
Formula
Interest savings = baseline interest - interest with extra payments
- Mortgage balance is the amount still owed.
- Rate and remaining amortization estimate the baseline schedule.
- Extra monthly payment is applied toward principal in the estimate.
Worked example
For a $400,000 mortgage at 5% with 25 years remaining, adding $250 per month may reduce both the payoff time and the estimated interest paid.
Common mistakes
- Assuming extra payments are allowed without limits.
- Putting every spare dollar into the mortgage without keeping an emergency fund.
- Comparing only the monthly cost and ignoring the interest savings.
FAQs
Where does the extra payment go?
In this estimate, the extra payment reduces principal, which can lower future interest.
Is an extra payment better than investing?
It depends on your mortgage rate, risk tolerance, tax situation and goals. This calculator focuses only on mortgage interest savings.
Can I make lump sum payments instead?
Many mortgages allow lump sum payments within limits. Use a lump sum payment calculator for a one-time payment estimate.