mCalculator logo
Debt Calculators

Debt Payoff Calculator

See exactly how long it will take to pay off any debt — and what the interest will cost you along the way.

Calculates month-by-month — the same way your lender accrues interest.

$
%
$
Time to payoff
4 yr 4 mo
At $300/mo, you pay $5,596 in interest.
Months to zero
52
Total interest
$5,596
Total paid
$15,596
Minimum to make progress
$183.33
Explain this result

Turn the numbers above into plain-language takeaways. Educational only — not financial advice.

Save & Compare Scenarios

Save the current inputs under a name, then reload or compare them side by side. Scenarios stay on this device only.

Overview

How the Debt Payoff Calculator Works

Every debt has a payoff date; the only question is whether you have chosen it or let the minimum payment choose it for you. This calculator runs the month-by-month arithmetic your lender uses — accrue interest, apply the payment, reduce the balance — so you can see exactly when a balance reaches zero and what the interest costs along the way. Increasing the payment by even $50 usually shortens the timeline far more than people expect.

Formula

The Math Behind the Calculator

Each month: Interest = Balance × (APR ÷ 12); Balance = Balance + Interest − Payment. The loop repeats until the balance reaches zero. Closed form: n = −log(1 − (B × r) / PMT) / log(1 + r), where B is the balance, r the monthly rate, and PMT the payment. If PMT ≤ B × r, the balance never falls.

Example

A Worked Example

A $12,000 balance at 19.99% with a $300 monthly payment takes 63 months to clear and costs $6,825 in interest. Raise the payment to $450 and it clears in 34 months with $3,200 in interest — the extra $150 a month saves $3,625 and nearly halves the timeline. Drop to $210 and the payoff stretches past 12 years, because almost the entire payment is going to interest.

How to use

How to Use the Debt Payoff Calculator

  1. 1Enter the current balance from your most recent statement, including any pending interest.
  2. 2Enter the APR exactly as stated; on credit cards, purchase and cash-advance APRs differ.
  3. 3Enter the fixed monthly payment you can commit to every month, not an optimistic figure.
  4. 4Check whether the payoff month is acceptable, then raise the payment in $50 increments to see the effect.
  5. 5Save two scenarios so you can compare a comfortable plan against an aggressive one.
Interpretation

What the Results Mean

  • Months to payoff is the date this debt disappears if you never add to the balance and never miss a payment.
  • Total interest is the true cost of the debt, and it is the number to compare against a balance transfer or consolidation offer.
  • A payoff longer than five years on a consumer debt usually signals that the payment is too close to the interest accrual.
  • If the tool reports the debt never clears, your payment is at or below the monthly interest and the balance grows.
Keep exploring

Smart Next Steps

What to explore next
Avoid

Common Mistakes to Avoid

  • Continuing to charge to a card while paying it down, which resets the timeline every month.
  • Paying the minimum, which on a typical card is engineered to keep the balance alive for a decade or more.
  • Focusing on a single debt without comparing snowball and avalanche ordering across all of them.
  • Ignoring a promotional rate that expires, after which the APR and the payoff date both jump.
  • Using the statement balance instead of the current balance, which understates the debt and the interest.
Scope

Limitations of This Calculator

  • It models a single debt with a fixed payment and fixed APR. Use the snowball or avalanche calculators for multiple debts.
  • Promotional or teaser rates that expire mid-term are not modeled.
  • New purchases, cash advances, late fees, and annual fees are excluded.
  • It assumes interest accrues monthly on the closing balance, whereas most cards use average daily balance, producing small differences.
  • It does not account for grace periods on cards paid in full each cycle.
Keep going

Related Calculators

Debt Snowball Calculator

Pay debts smallest-to-largest with a snowball strategy. Project the payoff order, timeline, and total interest for your full debt list.

Debt Avalanche Calculator

Pay highest-APR debts first with an avalanche strategy. Project the optimal payoff order, timeline, and the total interest saved.

Credit Card Payoff Calculator

Calculate how long it will take to pay off your credit card — or the payment needed to clear it by a target date.

Balance Transfer Calculator

Compare your current credit card payoff against a balance-transfer offer with an intro APR, transfer fee, and post-intro rate.

Learn

Related Guides

7 min read

Debt Snowball vs Avalanche: The Real Numbers on $30K in Debt

Side-by-side comparison of debt snowball and avalanche strategies on a realistic $30,000 mixed-debt payoff scenario.

Read guide
6 min read

Snowball vs. Avalanche: Which Debt Payoff Strategy Wins?

Compare the math of the debt avalanche with the psychology of the debt snowball, and pick the strategy that actually gets you debt-free.

Read guide
FAQ

Frequently Asked Questions

Why does my balance barely move at the minimum payment?+

Minimum payments are typically 1–3% of the balance, which on a high-APR card is only slightly more than the monthly interest. Almost nothing reaches the principal.

Should I pay off the smallest balance or the highest rate first?+

The highest rate saves the most money mathematically, which is the avalanche method. The smallest balance produces faster visible wins, which is the snowball method and works better for many people in practice.

How much faster is payoff if I add $100 a month?+

It depends on the APR and balance, but on a typical high-rate card an extra $100 often removes a third or more of the timeline. Run it both ways and compare.

Does this account for new purchases?+

No. It assumes the balance only decreases. If you keep charging to the account, the real payoff date will be later than shown.

Is it better to save or pay off debt first?+

Build a small starter emergency fund, then attack any debt with an APR above roughly 7–8% before adding more to savings, since guaranteed interest avoided beats uncertain investment returns.

Financial Disclaimer

This calculator is for educational and estimation purposes only. It does not provide financial, mortgage, tax, investment, or legal advice. Actual rates, payments, taxes, fees, insurance costs, eligibility, and loan terms vary by lender, location, credit profile, and market conditions. Always compare official offers and consult a qualified professional before making financial decisions.

Last updated June 2026 · Prepared by the mCalculator Editorial Team