Debt Payoff Calculator

There is no shortcut here — the balance is walked forward one month at a time, which is exactly how a lender does it. Each month interest is charged on what you still owe, then your payment is applied.

• Monthly rate r = APR ÷ 100 ÷ 12
• Each month: interest = balance × r, then balance = balance + interest − payment
• Repeat until the balance reaches zero; the final payment is whatever is left
• Total interest = the sum of every month's interest charge
• If payment ≤ balance × r, the balance never falls and there is no payoff date

Payoff time is the number of months until the balance reaches zero at the payment you entered, with interest charged on the remaining balance each month. Interest saved shows what the extra payment removes from the total.

Common mistakes and assumptions

• Entering a payment at or below the first month's interest — the balance never falls and there is no payoff date.
• Assuming a fixed payment when card minimums shrink as the balance drops, which stretches payoff far longer.
• Adding new charges during payoff, which this calculator does not model.

A $12,000 balance at 18.99% APR with a $400 monthly payment and $100 extra.

1. 1Monthly rate = 18.99 ÷ 1200 = 0.0158250.
2. 2First month's interest = $12,000 × 0.015825 = $189.90, so only $210.10 of a $400 payment reduces the balance.
3. 3At $400 a month the balance clears in 42 months with about $4,608 of interest.
4. 4At $500 a month it clears in 31 months with about $3,258 of interest.
5. 5That extra $100 saves roughly $1,350 and eleven months of payments.

What if my payment is too small?

If the payment does not cover one month of interest, the balance grows and there is no payoff date. The calculator tells you the exact interest figure you have to beat.

Should I attack the highest rate or the smallest balance?

Highest rate first costs the least in interest. Smallest balance first (the snowball) costs a bit more but gives quicker wins, which helps some people stay with it. Run each debt through this calculator to see the real difference before choosing.

Does this account for new purchases?

No. It assumes you stop adding to the balance. New charges push the payoff date out and add interest.

Is the interest calculated daily?

This uses monthly periods. Most cards compound daily, which adds a small amount of interest — expect your statement to run slightly higher than the estimate here.