Student Loan Calculator

Estimate payment amount, total interest, total paid, and payoff date for a fixed student loan with optional extra payments.

How to Use

  1. Enter your loan balance, interest rate, and repayment term.
  2. Select a payment frequency and optional start date.
  3. Add an extra payment if you want to see how faster payoff changes results.
  4. Open “Show Work” to review the payment formula, assumptions, and amortization math.
Results
Calculated from your balance, APR, term, and payment settings.
Scheduled Payment
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Total Paid
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Total Interest
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Payoff Date
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Total Payments
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Effective Loan Cost
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Enter your loan details to generate an estimate.

Quick Summary

  • Monthly or periodic payment estimate will appear here.
  • Extra payment impact will appear here.
  • Estimated payoff timeline will appear here.
Loan Inputs
Fixed-payment estimate for standard amortizing student loans.
Original principal or current balance.
Use nominal annual rate such as 4.99 or 6.80.
Common terms are 5, 10, 15, 20, or 25 years.
Monthly is standard for most student loans.
Optional extra amount added to each scheduled payment.
Optional fee to include separately or roll into balance.
Used to estimate a payoff date.
Standard mode matches typical payment-style display.
Show Work (step-by-step)
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Work is shown using the amortized loan formula and the selected payment frequency.

Payment Breakdown

Principal Portion (First Payment)
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Interest Portion (First Payment)
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Extra Payment Savings
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Time Saved
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Amortization Preview

Shows the starting portion of the repayment schedule. Full schedule can be generated in JS.

Amortization preview table
# Date Payment Principal Interest Balance
Enter loan details to preview the amortization schedule.

Student Loan Formulas

Base payment formula: M = P × r × (1 + r)^n / ((1 + r)^n − 1)

Used for fixed-payment amortizing loans when the rate and payment schedule remain constant.

  • M = payment per period
  • P = starting principal or current balance
  • r = periodic interest rate
  • n = total number of payments
  • Total paid = payment × number of payments
  • Total interest = total paid − principal
Actual federal or private loan servicing can differ because of capitalization events, autopay discounts, variable rates, deferment, forbearance, or income-driven repayment plans.

FAQ

Does this calculator include extra payments?

Yes. Add an extra payment per period to estimate faster payoff, lower total interest, and fewer payments overall.

Can I use this for federal and private student loans?

Yes, for fixed-payment estimates. It works best when the APR and payment schedule are known and stable.

Will this match my exact loan servicer bill?

Not always. Real servicing may include interest accrual timing differences, capitalization, fees, discounts, or plan-specific rules.

What if I pay biweekly instead of monthly?

Select biweekly to estimate how more frequent payments affect payoff timing and total interest under the same APR assumptions.

Tool Info

Last updated:

Updates may include repayment logic refinements, payoff scheduling improvements, and better amortization handling.