Estimate monthly payments and total interest on student loans.
Enter your loan amount, annual interest rate, and repayment term in years.
Monthly payment
$0
Total interest
$0
Total paid
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The Student Loan Calculator estimates your monthly payment, total interest, and total amount paid over the life of a student loan using the standard amortization formula. Enter your loan amount, annual interest rate, and repayment term in years. The calculator instantly shows your monthly payment and breaks down how much of the total goes to principal versus interest.
M = P × r(1+r)^n ÷ ((1+r)^n − 1)
Where:
Suppose you borrow $40,000 at 6.5% annual interest with a 10-year repayment term:
Student loans come in two main types: federal and private. Federal loans (in the United States) include Direct Subsidized, Direct Unsubsidized, and Direct PLUS loans. They generally offer lower fixed interest rates, income-driven repayment plans, and forgiveness programs. Private loans from banks and credit unions typically have higher variable rates and fewer protections, but can fill gaps when federal loans are insufficient.
The single most important number to understand is the annual interest rate, because interest compounds dramatically over a 10-20 year repayment term. A $40,000 loan at 5% interest costs about $10,900 in interest over 10 years, while the same loan at 8% costs about $18,000. Shopping for the lowest possible interest rate — by improving your credit score, applying with a co-signer, or comparing multiple lenders — can save thousands of dollars over the life of the loan.
The calculator reveals a powerful insight: extending the repayment term lowers your monthly payment but increases total interest dramatically. A $40,000 loan at 6.5% over 10 years costs $453/month and $14,438 in interest. The same loan over 20 years costs $298/month but $31,497 in interest — more than double. Choose the shortest term you can afford.
Even better, make extra payments when you can. Paying an extra $100 per month on a 10-year, $40,000 loan at 6.5% will pay off the loan 32 months early and save about $4,800 in interest. Because student loans typically have no prepayment penalty, every extra dollar directly reduces principal and the interest that principal would have accrued. Use this calculator to model different scenarios and find the payoff strategy that fits your budget.
Monthly payment uses the standard amortization formula: M = P × r(1+r)^n ÷ ((1+r)^n − 1), where P is principal, r is monthly interest rate (annual rate ÷ 12), and n is total number of monthly payments.
Federal student loans in the US for 2024-2025 range from 5.5% (undergraduate Direct Subsidized/Unsubsidized) to 7.05% (Direct PLUS for parents/grad students). Private student loans range from 4% to 13% depending on credit score.
The standard federal repayment plan is 10 years (120 monthly payments). Extended and income-driven plans can stretch to 20-25 years. Private loans typically offer 5, 10, 15, or 20-year terms.
The calculator shows this. As a rule, on a 10-year loan at 6% interest, you will pay roughly 33% of the principal in interest. On a 20-year loan at the same rate, you will pay about 72% of principal in interest.
Yes. Federal student loans have no prepayment penalty. Most private loans also allow early payoff without penalty. Even small extra payments can save thousands in interest over the loan's life.
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