Student Loan Calculator
Compare student loan repayment plans side by side. See monthly payments and total interest for standard, graduated, and extended plans.
The cheapest monthly payment is rarely the cheapest loan. This calculator compares the 10-year standard plan against a graduated plan (payments that start low and rise) and the 25-year extended plan, so you can see exactly what each choice costs in total interest.
How to use this calculator
- Enter your total student loan balance.
- Enter the interest rate (APR) — use a weighted average if you have multiple loans at different rates.
- Click Calculate.
- Compare the three plans: monthly payment now versus total interest over the life of the loan.
- Pick the plan with the highest payment you can reliably afford — it saves the most interest.
The formula
Standard and extended plans use the amortizing-loan formula: payment = P × r(1+r)^n ÷ ((1+r)^n − 1) with n = 120 or 300 months. The graduated plan starts at half the standard payment and steps up every 24 months, with the step size solved so the balance reaches zero at month 120.
Worked example
A $30,000 student loan at 6.8% APR: the standard 10-year plan costs $345.24/month and $11,428.92 in total interest. The graduated plan starts at $172.62/month, rises to $571.53, and costs $14,649.28 in interest. The 25-year extended plan drops the payment to $208.22/month but costs $32,466.49 in interest — nearly three times the standard plan.
Frequently Asked Questions
Which repayment plan pays the least interest overall?
The standard 10-year plan: fixed payments clear the balance fastest of the three. In the worked example, standard costs $11,428.92 in interest versus $14,649.28 graduated and $32,466.49 extended on a $30,000 loan at 6.8%. If the standard payment fits your budget, it's the cheapest path.
How does the graduated plan in this calculator work?
Payments start at half the standard payment — never below one month's interest, so the balance can't grow — and step up in equal increments every two years, calibrated so the loan is fully repaid in 10 years. Real federal graduated plans follow a similar shape, but the exact steps vary by loan servicer.
When does the extended plan make sense?
When the standard payment doesn't fit your budget and the alternative is missing payments. You trade a much lower monthly bill for dramatically more interest — in the example, $208.22/month but $32,466.49 in total interest, nearly triple the standard plan. Federal extended plans also require a balance over $30,000.
Should I refinance my student loans?
Refinancing federal loans into a private loan can lower your rate but permanently forfeits federal protections: income-driven plans, deferment, and forgiveness programs. Run the numbers here with your current rate versus the refinance offer, and only refinance federal loans if the savings clearly outweigh losing those safety nets.
Do extra payments help more on student loans than other debt?
Extra payments help any amortizing loan, but prioritize higher-rate debt first. If your student loan is at 5% and your credit card is at 22%, every extra dollar earns a bigger return wiping out the card. Use the debt snowball calculator to rank multiple debts.