Debt payoff calculator
When is your loan or mortgage gone — and what an extra payment buys you.
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Debt-free in 21 years 7 months
around May 2048
- Monthly payment
- 1,800
- Total interest
- 215,024
- Total paid
- 465,024
The extra 100/mo makes you debt-free 2 years 4 months sooner and saves 26,326 in interest.
The schedule assumes a fixed rate and steady payments. Early-repayment fees, insurance and rate changes are not included — check your loan contract before overpaying. Educational only, not financial advice.
In the app
Debt analysis
Available in the Nummira app as Debt Advisor: AI reads the loans you track, projects the payoff and shows where an early repayment saves the most.
Not financial advice.
Continue in the app
Nummira runs this math live on your real portfolio — no spreadsheets to update.
Continue in the appA $250,000 mortgage at 6.5% with an $1,800 monthly payment is fully repaid in about 21 years 7 months and costs about $215,000 in interest. An extra $100 a month makes you debt-free 2 years 4 months sooner and saves about $26,300 — try your own numbers above.
How the payoff is calculated
We use standard loan amortization with a nominal monthly rate — the annual rate divided by 12, the convention banks use. Each month interest accrues on the remaining balance; your payment covers it first and the rest reduces the principal. The exact term follows n = −ln(1 − P·i/M) / ln(1 + i), where P is the balance, M the monthly payment and i the monthly rate.
Why a small extra payment saves so much
Every extra unit of money goes straight to the principal, so all the future interest it would have carried disappears. On a $20,000 loan at 10% with a $400 payment, an extra $100 a month cuts the payoff from about 5 years 5 months to 4 years 1 month and saves roughly $1,550 of interest — and the earlier in the schedule you overpay, the bigger the effect.
The minimum-payment trap
If the payment doesn't exceed the interest accrued each month, the balance never falls and the loan mathematically never ends. This calculator refuses to invent a date in that case: it shows the interest-only threshold so you can see how far above it your payment needs to be.
Debt paid off? Point the freed-up payment at a goal with the savings calculator.