Extra Payment Calculator
Add extra principal to any mortgage or loan and see your new payoff date and interest saved.
Extra Payment Calculator
Your Loan
Extra Principal
Tell your servicer to apply extra money to principal, not to next month's payment.
| Year | Interest | Ending Balance |
|---|---|---|
| 1 | $16,074 | $244,007 |
| 2 | $15,672 | $237,612 |
| 3 | $15,244 | $230,790 |
| 4 | $14,787 | $223,510 |
| 5 | $14,299 | $215,743 |
| 6 | $13,779 | $207,455 |
| 7 | $13,224 | $198,613 |
| 8 | $12,632 | $189,179 |
| 9 | $12,000 | $179,112 |
| 10 | $11,326 | $168,371 |
| 11 | $10,607 | $156,912 |
| 12 | $9,839 | $144,684 |
| 13 | $9,020 | $131,638 |
| 14 | $8,147 | $117,718 |
| 15 | $7,214 | $102,866 |
| 16 | $6,220 | $87,019 |
| 17 | $5,158 | $70,110 |
| 18 | $4,026 | $52,070 |
| 19 | $2,818 | $32,821 |
| 20 | $1,529 | $12,283 |
| 21 | $262 | $0 |
Based on your results — what to do next:
Prefer a lower payment instead?
Instead of $200/mo extra, a $20,000 lump sum could be recast to cut your $1,639 payment.
Could a lower rate save even more?
Your 6.5% rate costs $281,000 over the remaining term — see if refinancing beats extra payments.
Pay down debt or invest?
Your $200/mo is a guaranteed 6.5% return — compare it with a market return.
An extra payment calculator shows how much interest you save and how many months you cut by paying more than the scheduled amount on a loan. Enter your balance, rate, and years remaining, then add a monthly extra or a lump sum to see the new payoff date and total interest saved.
How the Extra Payment Math Works
① Scheduled payment
M = B × i ÷ (1 − (1 + i)−n)
i = APR ÷ 12, n = months remaining, B = balance
② Each month with extra
Interest = Balance × i; Principal = (M + Extra) − Interest
Balance falls faster, so each later month has less interest
③ Interest saved
Saved = Interest(no extra) − Interest(with extra)
Compare the two amortization schedules
| Variable | Meaning | Typical Value |
|---|---|---|
| B | Current principal balance | Your latest statement |
| APR | Annual interest rate | 3–9% for mortgages |
| n | Months remaining | Years × 12 |
| Extra | Added principal per month | $50–$500 is common |
Worked Example — Balance $250,000, 6.5% APR, 27 years remaining
- Scheduled payment: $1,622/month
- Add $200/month of extra principal
- Payoff drops from 27 years to about 22 years 2 months
- Interest saved: roughly $68,000
💡 Pro-Tip
Extra principal is a guaranteed, tax-free return equal to your loan rate. Paying down a 6.5% loan earns 6.5% with zero risk. Early extra dollars matter most, because they remove principal that would have accrued interest for decades. Always instruct your servicer to apply the extra to principal, and confirm there is no prepayment penalty.
Extra Payment Calculator FAQ
How much will an extra $200 a month save on my mortgage?
On a $250,000 balance at 6.5% with 27 years left, an extra $200 per month cuts about five years off the loan and saves roughly $68,000 in interest.
Is it better to make extra payments or invest?
Extra payments earn a guaranteed return equal to your loan rate. If your rate is above what you expect to earn after tax from investments, paying down debt wins; at low rates, investing may come out ahead. Many people split the difference.
Do extra payments lower my monthly payment?
No. Extra payments shorten the loan but the required payment stays the same. To lower the payment you need a recast or a refinance.
Should I make one lump-sum payment or smaller monthly extras?
Interest is charged on the balance, so the earlier extra principal arrives, the more you save. A lump sum now beats the same total spread over time, but regular extras are easier for most budgets.
Next Step: Related Calculators
Mortgage Payoff Calculator
Pay your mortgage off early — see months saved, interest saved, and new payoff date with extra payments.
Mortgage Refinance Calculator
Break-even analysis, monthly savings, and net benefit over your planned stay.
Loan Amortization Calculator
Monthly payment + full amortization schedule for any loan.