Student Loan Calculator

Q: What is the standard student loan repayment plan?

Federal loans default to the Standard plan: fixed payments over 10 years. On $35,000 at 6.5%, that's about $397 per month and roughly $12,700 in total interest.

Q: Should I pay off student loans early or invest?

Extra payments earn a guaranteed return equal to your rate. High-rate private loans (8%+) are strong payoff candidates; low-rate federal loans compete with investing and are also eligible for income-driven plans and potential forgiveness, which prepaying can waste. Prioritize by rate and loan type.

Q: How does student loan interest work?

Student loan interest typically accrues daily on the outstanding principal (simple daily interest). Unpaid interest can capitalize — get added to principal — after deferment or plan changes, which then increases the interest that accrues after that point.

See your monthly payment, total interest, and payoff date on any repayment timeline — and what extra payments do to both.

Monthly payment

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Total interest

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Total repaid

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Payoff time

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Saved with extra payments

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The repayment formula

M = P × [ r(1 + r)ⁿ ] / [ (1 + r)ⁿ − 1 ]

Worked example — the average graduate

Balance $35,000 at 6.5% on the 10-year Standard plan:

Payment: $397/mo · total interest: ≈ $12,700 · total repaid: ≈ $47,700

Adding $100/mo extra pays it off in about 7.7 years and saves roughly $3,300 of interest.

Term length vs. total cost ($35,000 at 6.5%)

Plan length	Monthly payment	Total interest
5 years	$685	$6,100
10 years	$397	$12,700
15 years	$305	$19,900
20 years	$261	$27,600
25 years	$236	$35,900

On the 25-year timeline, interest exceeds the original balance. Longer terms are sometimes necessary for cash flow — but treat them as a floor, not a plan, and send extras when you can.

Federal borrowers: know your options first

Before optimizing payoff speed, check what your federal loans qualify for: income-driven repayment (payments tied to income), Public Service Loan Forgiveness if you work in government or nonprofits, and deferment protections. Aggressively prepaying a loan that would have been forgiven is money lost. Private loans have none of these safety nets — they're usually the right target for extra payments, highest rate first (see the debt payoff calculator for ordering multiple loans). Refinancing federal loans into private ones trades those protections for a lower rate — do that math carefully.

Frequently asked questions

What is the standard student loan repayment plan?

Fixed payments over 10 years — about $397/mo and $12,700 of interest on $35,000 at 6.5%.

Should I pay off student loans early or invest?

Prepay high-rate private loans first; low-rate federal loans with forgiveness potential often deserve minimum payments while you invest instead.

How does student loan interest work?

It accrues daily on principal; unpaid interest can capitalize after deferments, raising future interest.

Related calculators

Note: Models a fixed-rate amortized loan; income-driven federal plans compute payments differently. Not financial advice. Last reviewed: July 2026.