Loan Payoff Date Calculator

Calculate exactly when you will be debt-free. Find your payoff month, total interest paid, and how extra payments dramatically shorten the timeline and cut interest.

📅 Debt💰 Time = −log(1−r·B/P) / log(1+r)
Current loan balance ($)
Annual interest rate (%)
Monthly payment ($)
Extra monthly payment ($, optional)
Please enter valid values.

Formula & Reference

VariableFormulaUnits
Loan Payoff Date CalculatorTime = −log(1−r·B/P) / log(1+r)months to payoff

Step-by-Step Examples

Example 1
Car Loan

$15k at 6%, $300/mo.

  • 62 months to payoff (~5 years)
  • Add $100 extra: 48 months — 14 months sooner!
✓ 62 months, or 48 with $100 extra
Example 2
Student Loan

$30k at 5%, $300/mo.

  • 162 months (13.5 years!)
  • Add $200 extra: 87 months — 6+ years saved!
✓ 162 months normally; 87 with $200 extra
Example 3
Credit Card

$5k at 22%, $150/mo minimum.

  • 46 months + $1,891 interest
  • Pay $250/mo: 26 months, save $836 in interest
✓ $250/mo saves 20 months and $836 interest

Real-World Applications

Common Mistakes to Avoid

⚠️
Paying only minimums on high-interest debt

Minimums on 22% cards barely touch principal. A $5k balance can take 15+ years on minimums.

⚠️
Not calculating extra payment impact first

Even $50 extra on a 5-year loan often saves 6–12 months. Run numbers before committing to a strategy.

⚠️
Ignoring the interest rate hierarchy

Pay highest-rate debt first (avalanche) for maximum interest savings.

Frequently Asked Questions

How is payoff date calculated?
months = −log(1−r×B/P) / log(1+r) where r=monthly rate, B=balance, P=payment. Add result to today.
What if payment barely covers interest?
If monthly payment ≤ balance × monthly rate, you’ll never pay off the loan. Must exceed this floor.
How much do extra payments help?
On a 30-year mortgage, $200 extra often saves 7–8 years and $50k+ in interest.
Debt avalanche vs snowball?
Avalanche (highest rate first): mathematically optimal. Snowball (lowest balance first): motivational. Both work; pick what keeps you going.
Pay off debt vs invest?
If debt rate exceeds expected return (usually credit cards), pay debt first. If below (often mortgages), investing may be better mathematically.

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