Example 1
- Balance: 3,000
- Payment: 300
- Mode: no interest
~10 months
No interest: 3000 ÷ 300 = 10 months. With interest the horizon is longer.
Debt payoff calculator
Enter the current balance, monthly payment, and choose No interest or With interest. At 3,000 and 300 with no interest the result is 10 months. At 12,000, 400, and 18% a year the calculator returns 41 months and about 4,061.98 in interest.
Results
Current debt / balance, Monthly payment, Annual interest rate (%) and Extra monthly payment (optional). The result shows up here.
Horizon for one balance and a fixed payment. Contract comparison: loan overpayment. Full table: amortization schedule. An estimate, not an amendment.
How results are calculated
Balance12,000
Payment400
Rate18%
Time41 mo.
This debt-repayment calculator estimates how many months it takes to clear one balance at a fixed payment. In No interest mode 3,000 at 300 a month is exactly 10 months and 3,000 paid. In With interest mode 12,000 at 400 and 18% a year takes 41 months, and interest is about 4,061.98. 12,000 ÷ 400 alone is 30 months: the extra 11 months are the cost of 18%.
This calculator helps with a credit-card balance or a small loan when you know the balance and a fixed payment, not a full annuity contract. An extra 150 a month and a one-time 500 in month 1 on the same 12,000, 400, and 18% shorten payoff to 26 months, and interest falls to about 2,414.36. That is 15 months less than 41. Extras are compared with the base payment pace, without a full table.
Required fields are Current debt / balance and Monthly payment. The mode switch shows or hides Annual interest rate (%). Options include Extra monthly payment, One-time extra, the month number for the lump, and Start date. Start date sets an estimated debt-free date. The calculator does not build a payment from amount and rate: you enter the payment.
Loan overpayment starts from remaining principal and a contractual annuity. The amortization schedule builds the full table. Loan installment computes 1,112.22 from 50,000 at 12% over 5 years. Here you start from the balance and payment you already have. Header currency only labels amounts. A comma and a period in 18.0 mean the same rate.
The calculator needs a positive balance and a payment that, in interest mode, must cover monthly interest. At 12,000 and 18% monthly interest is 180, so 400 works and 100 is too low. This is a teaching horizon, not a credit decision.
Enter 3,000 and 300, leave No interest selected, click Calculate, and check 10 months. Then try 12,000, 400, and 18% in With interest mode to see 41 months.
How to use
- Enter Current debt / balance, for example 3,000, and Monthly payment, for example 300.
- Choose No interest or With interest. In the second mode enter Annual interest rate (%), for example 18.
- Optionally add Extra monthly payment, a one-time extra and month number, and Start date.
- Click Calculate. 3,000 / 300 with no interest is 10 months. 12,000, 400, and 18% is 41 months and about 4,061.98 in interest.
- Contractual overpayment comparison lives on loan overpayment. The full table lives on the amortization schedule.
Formula
No interest: months ≈ balance ÷ payment (the last payment may be smaller). With interest in month k: interest = balance × (r/100/12); payment = scheduled payment + optional extras; new balance = balance + interest − payment.
The simulation ends when the balance reaches zero, or when the payment does not cover that month’s interest. At 12,000 and 18% the first month’s interest is 180.
At 3,000 and 300 with no interest the result is 10 months. At 12,000, 400, and 18% payoff takes 41 months and interest is about 4,061.98. This is a teaching model, not a lender amendment.
Balance horizon at a fixed payment
One balance and a fixed payment. At 3,000 and 300 with no interest the result is 10 months. At 12,000, 400, and 18% a year the calculator returns 41 months and about 4,061.98 in interest.
- balance
- Current debt / balance. 3,000 / 300 with no interest = 10 months. 12,000 at 400 and 18% takes 41 months, not 30.
- interest
- With interest mode accrues interest on the balance. 18% at 12,000 and 400 yields about 4,061.98 total, longer than 12,000 ÷ 400.
- payment
- Fixed monthly payment. 300 on 3,000 with no interest clears in 10 payments. +150 and +500 once shorten the 18% case to 26 months.
Examples
Example 2
- Balance: 12,000
- Payment: 400
- 18% annual
41 months
Interest ≈ 4,061.98
Part of each payment covers interest on the balance; at 12000, 400, and 18% payoff takes 41 months.
Example 3
- Same as example 2
- +150/mo and +500 once
26 months
Interest ≈ 2,414.36
−15 mo. vs payment only
Extra 150 and a 500 one-time payment at 12000 / 400 / 18% shorten payoff versus payment 400 alone.
Example 4
- Current debt / balance: 3,000
- Monthly payment: 300
- Mode: no interest
~10 months
No interest: 3000 at 300 per month clears in 10 months (3000 ÷ 300).
When to use this calculator
- Use Debt payoff when you have one debt balance and a fixed monthly payment, and want to know when the balance reaches zero.
- This tool is useful for payoff planning, but it is not meant for designing a new loan offer.
- If you want to size the instalment for a new loan, use Loan instalment.
- If you want to analyze overpayments on an existing amortizing loan, choose Loan overpayment or Repayment schedule.
Common mistake
- A payment that is too low relative to the interest rate may fail to reduce the debt meaningfully - that is why the “never payoff / too low payment” warning matters more than the raw nominal output.
Related calculators
FAQ
What is a debt payoff calculator on this page?
The calculator estimates how many months one balance takes to reach zero at a fixed monthly payment — with no interest or with a fixed annual rate. At 3000 and 300 with no interest that is 10 months. At 12000, 400, and 18% payoff takes 41 months and about 4061.98 in interest. An educational horizon, not a bank contract.
How is time to payoff calculated?
In No interest mode the calculator divides balance by payment. At 3,000 and 300 a month the result is 10 months. In With interest mode each month adds interest on the balance, then subtracts the payment. At 12,000, 400, and 18% payoff takes 41 months and interest is about 4,061.98.
Does the calculator compute the payment from balance and rate?
No. You enter the monthly payment. An annuity from amount, rate, and years lives on the loan installment page. Here you start from a balance and a fixed payment you already know.
When does the rate field appear?
After you choose With interest. In No interest mode the field stays hidden, and 3,000 at 300 a month remains 10 months.
How do the extra monthly and one-time payments work?
The extra monthly amount is added to the payment each month. The one-time lump applies on the month number in Apply one-time extra at month #. At 12,000, 400, 18%, an extra 150 a month and 500 in month 1, payoff takes 26 months and interest is about 2,414.36 — 15 months shorter than 41.
How is this different from loan overpayment?
Loan overpayment compares a contractual annuity with extras. Here you see the horizon for one balance and a fixed payment you already know, without the full table.
Is this a debt snowball calculator for multiple debts?
No. The calculator uses one balance and one fixed payment. It does not order a list of cards or loans from the smallest balance to the largest.
Is this a credit-card payoff calculator with minimum payments?
No. You enter the payment you plan to make. The calculator does not look up issuer minimums or revolving statement cycles.
What happens if the payment is below monthly interest?
The balance does not fall. At 12,000 and 18% monthly interest is 180, so a payment of 100 is too low. The calculator asks for a payment above that amount.
What is Start date for?
It sets an estimated debt-free date. Without a date the result shows months only, with no calendar date.
Does a comma in the rate work?
Yes. 18,0 and 18.0 are the same rate. Header currency only labels the result and does not convert the balance.
Is the result from a bank contract?
No. It is an estimate from the balance, payment, and optional rate you enter. An offer may compute differently. It is not a credit decision.
Where is the month-by-month table?
On the amortization schedule page. Here you see the horizon and totals, not every row.
Knowledge sources
The horizon is one balance and a fixed payment you enter. It is an estimate, not an amendment.
Page updated October 29, 2026