Loan Payoff Calculator
Find months to pay off a loan, total paid, and interest from balance, APR, and monthly payment.
What it does
A loan payoff shows how long it takes to erase a balance and how much interest you will pay along the way. Interest compounds monthly on the remaining balance.
The tool above takes the loan balance, annual percentage rate, and monthly payment, then shows months to pay off, total paid, and interest paid. Enter your numbers and read the result.
Your payment must cover at least the monthly interest plus something toward principal, or the balance never falls and the tool rejects the input.
Paying even a little extra each month shortens the payoff and cuts total interest, so every extra dollar helps.
How to use
- Enter the current loan balance.
- Enter the annual percentage rate as a percent.
- Enter the monthly payment you plan to make.
- Read months to pay off first.
- Read total paid and interest paid beside it.
Formula
- balance
- Current loan balance, in dollars.
- APR
- Annual percentage rate, in percent.
- payment
- Monthly payment toward the loan, in dollars.
- months
- Count of monthly payments until the balance is zero.
Interest is calculated on the remaining balance each month. The loop stops after 1,200 months (100 years) on hostile inputs so it never runs forever.
Worked example
Example: $5,000 balance, 12% APR, $200 monthly payment
Balance 5,000, APR 12 percent, monthly payment 200.
- Monthly rate: 12 / 100 / 12 = 1 percent.
- First month interest: 5,000 x 0.01 = $50.00.
- Of the $200 payment, $50.00 covers interest and $150.00 reduces principal.
- Repeating month by month, the loan ends in 29 months.
- Tool shows 29 months, total paid $5,782.44, interest $782.44.
Reference table
| Monthly payment | Months | Total paid | Interest |
|---|---|---|---|
| $100 | 80 months | $6,152.30 | $1,152.30 |
| $200 | 29 months | $5,782.44 | $782.44 |
| $300 | 19 months | $5,515.08 | $515.08 |
| $500 | 11 months | $5,302.85 | $302.85 |
Limits
- This assumes a fixed APR and fixed monthly payment with no fees or extra charges.
- Variable-rate loans change the rate over time, so results shift.
- Skipped or late payments are not modeled.
- The payoff is capped at 1,200 months so the calculation always ends.
Common mistakes
- Entering a payment below the monthly interest, which never pays off the loan.
- Confusing APR with the effective annual rate.
- Forgetting that interest falls as the balance falls.
- Comparing loans by monthly payment alone instead of total interest.
- Assuming extra payments always go to principal without checking the lender.
Try it yourself
Quick checks. Answers sit tucked under each question.
$3,000 balance, 10% APR, $150 monthly?
22 months, total paid $3,295.46, interest $295.46.
$10,000 balance, 8% APR, $300 monthly?
38 months, total paid $11,346.95, interest $1,346.95.
$1,000 balance, 18% APR, $50 monthly?
24 months, total paid $1,197.83, interest $197.83.
Questions
How is payoff time found?
By applying interest and subtracting the payment each month until the balance reaches zero.
What if my payment only covers interest?
The balance never falls, so the loan is never paid off. The tool rejects that input.
Does paying extra help?
Yes. Extra principal shortens the term and reduces total interest.
Is this for mortgages too?
It works for any fixed-payment loan, though mortgages often include escrow, taxes, and insurance outside this math.
Does it include fees?
No. Fees, insurance, and taxes sit outside this calculation.
Why is it capped at 1,200 months?
So the calculation always ends, even for unrealistic inputs.
Sources
- Consumer Financial Protection Bureau: Debt and Loans
- Board of Governors of the Federal Reserve System: Consumer Credit