Student Loan Payoff Calculator
Payoff date, total interest and the effect of paying extra.
Enter your values
ⓘ Live results
Results
- Payoff time with extra payments
- 6 yr 11 mo
- Payoff time without extra
- 10 yr 5 mo
- Time saved
- 3.5 years
- Total interest with extra
- $9,273.56
- Interest saved
- $5,089.92
- Total paid
- $47,273.56
Quick answer
Extra payments go straight to principal, so every additional dollar removes all the future interest that dollar would have accrued.
n = −ln(1 − r × B ÷ P) ÷ ln(1 + r)
How to use the Student Loan Payoff Calculator
- 1Enter your total balance and weighted average rate.
- 2Enter the required monthly payment.
- 3Try different extra payments to see the time and interest saved.
Worked example
Using the values the calculator loads with:
Inputs
- Loan balance38000 $
- Interest rate6.5 %
- Monthly payment420 $
- Extra payment150 $
Results
- Payoff time with extra payments6 yr 11 mo
- Payoff time without extra10 yr 5 mo
- Time saved3.5 years
- Total interest with extra$9,273.56
- Interest saved$5,089.92
- Total paid$47,273.56
Frequently asked questions
Should I target the highest rate first?
Yes, mathematically — the avalanche method saves the most interest. The snowball (smallest balance first) wins on motivation if that keeps you going.
Do extra payments go to principal?
Only if you tell the servicer. Otherwise they may be applied as an advance payment on next month's bill, which saves far less.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.