Free Mortgage Amortization Calculator
Calculate how much time and interest you save by making extra monthly payments on your mortgage. Free. No signup required.
| Year | Principal Paid | Interest Paid | Remaining Balance |
|---|---|---|---|
| Year 5 | $34,579.67 | $98,777.39 | $285,420.33 |
| Year 10 | $82,397.03 | $184,317.09 | $237,602.97 |
| Year 15 | $148,519.70 | $251,551.48 | $171,480.30 |
| Year 20 | $239,955.28 | $293,472.96 | $80,044.72 |
| Year 24 | $320,000.00 | $302,713.69 | $0.00 |
Sample years from your amortization schedule with the extra $200.00/mo payment applied — principal paid, interest paid and remaining balance, year by year.
- Standard Payoff Time30.1 years
- Interest Saved$105,428.67
- Standard Monthly Payment$2,022.62
About the Free Mortgage Amortization Calculator
Amortization schedules are built so that early payments go almost entirely to interest and barely touch the principal — which is exactly why even a modest extra payment applied in those early years has an outsized effect on how much interest you end up paying overall. This calculator runs your full amortization with and without an extra monthly payment, showing the actual years and dollars it saves rather than a rough rule of thumb.
It's for homeowners deciding whether extra payments are worth prioritizing over other goals — paying down a mortgage faster versus investing that same money elsewhere, or simply wanting to see the real payoff-date impact of a specific extra amount before committing to it.
Your loan balance, your rate, how much extra you're actually able to put toward it — these are numbers worth testing privately before deciding, and this calculator never sends them anywhere; everything runs in your browser.
How it’s calculated
Every extra dollar you pay goes straight to principal, which means every future month's interest is calculated on a smaller balance — the effect compounds over the life of the loan rather than staying flat. This calculator simulates the amortization month by month with your extra payment included, tracking the payoff date and total interest, and compares that against the standard schedule with no extra payment to isolate exactly what the extra payment is worth.
Frequently asked questions
Does paying an extra $100-200 a month on my mortgage really make a big difference?
Often yes, more than people expect — because that extra amount reduces principal directly and every future interest calculation is based on the lower balance, the compounding effect over 20-30 years can shave years off the loan and save tens of thousands in interest. Run your own numbers here to see the actual figure for your loan.
Should I make one extra payment a year or split it across all 12 months?
Mathematically, spreading extra payments across the year saves slightly more interest than one lump sum at year-end, since the balance is reduced sooner on average. In practice the difference is small — whichever is easier for you to actually stick with consistently matters more than the marginal timing gain.
Is there a penalty for paying off my mortgage early?
Most US mortgages originated in recent years don't have prepayment penalties, but it's not universal — check your loan documents or ask your servicer directly before assuming extra payments are penalty-free.
Do I need to tell my lender to apply extra payments to principal?
Usually yes — many servicers apply extra amounts to the next month's payment by default rather than directly to principal unless you specify otherwise, often through an online portal option or a note with your payment. Confirm with your servicer that extra payments are actually being applied the way you intend.
How much faster will I pay off my mortgage with extra payments?
It depends on your balance, rate, and how much extra you add — this calculator shows your exact standard payoff time against the accelerated one, side by side, using your real loan numbers instead of a generic estimate.
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