Working backward from a payoff date
Most people start a debt payoff calculation the other way around: "If I pay $X per month, when will I be done?" This calculator flips that question. Instead, you pick the finish line — say, "debt-free in 18 months" — and we calculate exactly how much you need to pay every month to hit that target, interest included.
This is especially useful when you have a real deadline in mind, like wanting to be debt free before a wedding, a home purchase, or the start of a new financial year. Instead of guessing at a payment amount and checking whether it's enough, you get the precise number up front.
How the math works
We use the same fixed-payment amortization formula banks use to calculate loan payments: it accounts for the fact that interest is charged on a shrinking balance each month, and solves for the constant monthly payment that brings your balance to exactly zero at the end of your chosen period.
A worked example
Suppose you owe $4,000 at 22% APR and want to be completely debt-free in 18 months. Plugging those numbers in, you'd need to pay about $248 per month. Over those 18 months you'd pay roughly $460 in total interest. If you stretched the same balance to 24 months instead, your monthly payment would drop to around $191 — but total interest paid would rise to about $584, since the balance has more time to accrue interest.
Choosing the right target
- Shorter timeframes mean higher monthly payments but less total interest — check that the required payment fits comfortably in your budget before committing.
- If the required payment feels too high, try the Minimum Payment Calculator to see the other extreme — what happens if you only pay the minimum — for context.
- If your APR is high, consider whether a balance transfer to a lower rate could shrink the required payment for the same target date.
- Once you know your required payment, use the Credit Card Payoff Calculator to double-check the full amortization schedule.