How Long Will It Take to Pay Off a Loan?

One dollar either side of a cliff

$5,000 balance at 18% APR. The interest alone is $75 a month.

Monthly payment	Result
$75	never clears — you owe $5,000 forever
$76	clears in 291 months (24 years), costing $17,107 in interest
$200	clears in 31.6 months, costing $1,314

One dollar separates "never" from "24 years". Another $124 takes it to under three.

The calculator returns a dash rather than a number when the payment can't clear the debt, because any number there would be a lie.

Why the cliff exists

Every month the balance grows by the interest charged and shrinks by your payment.

If the payment is smaller than the interest, the balance grows. Forever. There's no amount of patience that fixes it.

The threshold is simply balance × monthly rate — shown as its own output, because it's the first thing to check and almost nobody does.

That's what a credit card minimum is

A card minimum is typically a small percentage of the balance, calculated to sit just above this threshold.

Which is precisely why paying only the minimum takes decades and costs enormously. It's designed to clear the debt eventually, while maximising the time it takes.

Seeing the interest-only figure next to your actual payment is the fastest way to understand what a minimum payment really is.

The relationship is logarithmic, not linear

This is why small extra payments do more than they look like they should.

Doubling the payment doesn't halve the time — it cuts it by considerably more:

Payment	Months
$200	31.6
$250	24.0
$400	13.9

$50 more a month saves 7.6 months and $325 in interest. Doubling to $400 cuts it from 31.6 months to 13.9 — well under half.

Two things compound: every dollar above the interest goes straight against principal, and that principal then never accrues interest again for the whole remaining life of the loan.

The saving is biggest early, when the balance is largest — so acting now beats acting later by more than the delay alone suggests.

Look at the total interest once

A monthly payment is designed to feel manageable. A total is designed by nobody — which is exactly why it's the more honest number.

At $76 a month, you pay $22,107 to clear a $5,000 debt. The interest is more than three times what you borrowed.

Two assumptions that break it on a credit card

A fixed rate. Card rates are variable and can change.

No new borrowing. This is the big one. Continuing to spend on the card while paying it down is the commonest reason a payoff plan quietly fails — and no arithmetic here can see it.

Treat the answer as what happens if you stop using the card today, which is also the plan most likely to work.

Should you always overpay?

Usually, on high-rate debt — with two checks first.

Early repayment charges. Some fixed-term loans penalise exactly this behaviour.

What else the money could do. Paying off an 18% debt is a guaranteed 18% return, which beats almost anything else available. Overpaying a low-rate loan may not beat keeping an emergency fund.

The rate decides it, and the calculator shows you the saving so you can compare properly.

Print the payoff plan — it has a row per debt with the interest-only figure for each, because any debt sitting at or below that line needs fixing before the rest of the plan means anything.