Our Student Loan Calculator helps you estimate monthly payments, total interest, and payoff timelines so you can make smarter decisions about borrowing and repayment. Whether you have federal or private loans, a quick calculation can reveal how grace periods, capitalization, and extra payments impact your total cost.
How the Student Loan Calculator Works
At its core, student loan repayment is governed by a few key inputs: your loan amount (principal), annual percentage rate (APR), and the repayment term in years. The calculator converts your APR into a monthly rate and then applies an amortization formula to determine your estimated monthly payment. If your APR is 0%, the payment is simply the principal divided by the number of months in your term.
Many borrowers also experience a grace period before repayment begins. During this time, unsubsidized loans typically accrue interest. Depending on your loan type and agreement, that interest may be capitalized, which means it gets added to your principal, increasing the amount on which future interest is calculated. Our calculator lets you specify how interest is handled during grace—no accrual, accrual without capitalization, or accrual with capitalization—so your results better reflect reality.
Why Extra Payments Matter
Adding a small extra amount to your monthly payment can have an outsized impact on total interest and time to payoff. Extra payments go straight to principal after covering that month’s interest, reducing your balance faster. This lowers the interest charged in future months, accelerating your path to debt freedom.
- Pay off sooner: Even $25–$50 extra per month can shave months off your term.
- Save on interest: Less principal outstanding means less interest charged over time.
- Flexibility: You can pause extra payments when cash is tight and resume later.
Key Terms to Know
Principal
The original amount borrowed, or the remaining balance you owe today, excluding interest.
APR (Annual Percentage Rate)
The yearly cost of borrowing expressed as a percentage. The calculator converts APR to a monthly rate for amortization.
Grace Period
A set number of months after leaving school or dropping below half-time before required repayment begins. Interest treatment varies by loan type.
Capitalization
When accrued interest is added to your principal, causing you to pay interest on interest going forward. Avoiding or reducing capitalization can lower your total cost.
Tips for Using the Student Loan Calculator
- Enter the exact APR from your loan documents. Small differences change your monthly payment and total interest.
- Check your loan type. Subsidized loans may not accrue interest during grace; unsubsidized loans usually do.
- Model capitalization. If your lender capitalizes interest at repayment start, select that option to see the impact.
- Try extra payments. Test different extra amounts to find a realistic plan that fits your budget.
- Revisit after changes. If you recertify income, refinance, or switch plans, update inputs to keep your estimates current.
Common Scenarios
If you expect a six-month grace period with interest capitalization, you’ll likely start repayment with a higher principal than you borrowed. That increases your monthly payment and total interest. Conversely, if you make interest-only payments during grace (or your loan is subsidized), capitalization may be minimized or avoided, keeping your principal lower.
Considering extra payments? The calculator reveals potential interest savings and how many months you might shave off your term. This helps you weigh whether a small monthly change is worth the long-term benefit.
Limitations and Next Steps
This Student Loan Calculator provides estimates based on standard amortization. It doesn’t model complex federal plans like income-driven repayment (IDR), graduated schedules, or forgiveness programs. For personalized guidance, consult your servicer or a qualified advisor. Still, for most fixed-rate loans, these estimates offer a reliable starting point to plan your budget and repayment strategy.