$40k @ 5.5%, 120 months, $150 extra
- Standard P&I ≈ $434; baseline payoff 120 months, interest ≈ $12,093
- With $150 extra: payoff ≈ 83 months; interest ≈ $8,116
- Savings: ≈ $3,977 interest; ≈ 37 months faster
finance calculator
Student Loan Payoff Calculator (with Extra Payments)
See how extra monthly payments shorten your student loan payoff time and reduce total interest compared to the standard schedule.
Results
- Standard monthly payment
- $434
- Payoff time (standard)
- 120.00
- Payoff time with extra
- 83.00
- Total interest (standard)
- $12,093
- Total interest (with extra)
- $8,116
- Interest saved
- $3,977
- Months saved
- 37.00
How to use this calculator
- Enter your student loan balance, APR, and term.
- Enter the extra monthly amount you can pay.
- Review payoff time with and without extra, total interest in both cases, and savings.
Inputs explained
- Balance
- Current student loan principal.
- Term
- Remaining term in months.
- Extra payment
- Additional amount applied to principal each month.
How it works
We compute the standard amortized payment using balance, APR, and term.
We simulate monthly amortization with and without your extra payment.
Outputs show payoff time and total interest for both scenarios plus interest and months saved.
Formula
Standard payment = P × r / (1 − (1+r)^{−n}) where r = APR/12, n = term months.
Simulate amortization monthly with and without extra to derive payoff time and interest.When to use it
- Planning aggressive payoff strategies to clear loans sooner.
- Estimating interest saved before committing extra cash each month.
- Adjusting extra payments after a raise or bonus to see timeline changes.
Tips & cautions
- Ensure extra payments are applied to principal, not future installments—confirm with your servicer.
- Increase extra payments when possible; even small boosts can shave years off long terms.
- Consider refinancing only if it lowers rate without losing federal protections; this model assumes a fixed rate.
- Assumes fixed-rate amortization and consistent extra payments.
- Does not include servicer fees, capitalization changes, or income-driven plan nuances.
- No prepayment penalties assumed; check your loan terms.
Worked examples
$60k @ 6.2%, 180 months, $200 extra
- Standard P&I ≈ $513; baseline interest ≈ $32,308
- With $200 extra: payoff ≈ 111 months; interest ≈ $18,946
- Savings: ≈ $13,362 interest; ≈ 69 months faster
Deep dive
This student loan payoff calculator shows how extra monthly payments accelerate payoff and reduce interest compared to the standard schedule.
Use it to plan extra payments, see months and interest saved, and adjust your strategy as income changes.
FAQs
- Do I lose federal protections if I refinance?
- Refi can drop rate but may forfeit IDR/forgiveness. This model assumes a fixed-rate loan you keep.
- Can I prepay without penalty?
- Most student loans allow prepayment without penalty; confirm with your servicer.
- Income-driven plans?
- Not modeled. This assumes a standard amortization schedule with fixed payments.
- How to ensure extra goes to principal?
- Tell your servicer to apply extra to principal and keep payments due as scheduled.
- Variable rates?
- Not modeled; this assumes a fixed APR.
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