See how extra monthly payments shorten your payoff time and cut total interest.
What this calculator does
Adding a little to each mortgage payment can save years and a lot of interest. Enter your balance, rate and payment, plus an extra amount, to see the impact.
The calculator compares payoff with and without the extra.
How to use it
- Enter your current balance and rate.
- Enter your monthly payment.
- Add an extra amount to see the savings.
The maths behind it
each month interest = balance × rate ÷ 12
extra payment reduces principal faster
A worked example
Worked through, a current balance of 180,000, extra monthly payment of 200 produces a payoff with extra of 207. Underneath, Payoff without extra comes out at 279 months and Interest saved at $44,697.77. Change any field and every figure updates as you type.
FAQ
Do extra payments really help?
Yes — extra money goes straight to principal, which cuts the balance interest is charged on, compounding the savings.
Is it better than investing?
It depends on your rate versus expected investment returns and your risk tolerance. This is an estimate, not advice.
Should I tell my lender it’s extra principal?
Often yes, so the extra is applied to principal rather than future payments. Check your servicer’s process.