Comprehensive Guide
Learn more in our Loans & Mortgage Guide.
How it works
student loan calculator takes your inputs and produces monthly payment, total interest, total repaid, payoff time, months saved by extra. Repayment math for federal and private student loans — payment, interest, and the payoff schedule with rounded-up payments. You provide 4 inputs: Loan balance (currency, in dollars) (default: 38000 dollars); Interest rate (percent, in percent) (default: 6.5 percent); Repayment term (years, in years) (default: 10 years); Extra monthly payment (currency, in dollars) (default: 100 dollars). The calculator returns 5 outputs: Monthly payment (the primary result); Total interest (a secondary output); Total repaid (a secondary output); Payoff time (a supplementary figure); Months saved by extra (a supplementary figure). Loans and mortgages are amortized instruments where the split between interest and principal shifts every month. Understanding the total cost of borrowing — not just the monthly payment — is the difference between a sustainable debt load and one that erodes your net worth over time. This calculator reveals the full amortization picture. The underlying formula: M = P x r(1+r)^n / ((1+r)^n - 1) | standard term = 120 months With the default values, monthly payment is computed from the interaction of every input field — change any one of them and the result updates immediately, so you can stress-test different scenarios without re-entering the whole form. Adjust the inputs to match your real financial situation. The defaults are realistic starting points, but every person's circumstances differ — your actual income, expenses, rates, and timelines will produce a different answer. Use the tool iteratively: start with the defaults, then change one variable at a time to see which factor has the largest impact on your outcome.Formula
M = P x r(1+r)^n / ((1+r)^n - 1) | standard term = 120 months
Tips
- Federal loans: keep the borrower protections; private refinance only when the rate gap is clear and durable.
- An extra $50-100 a month on the standard plan saves years — the schedule shows the exact effect.
- Pay interest on unsubsidized loans while in school if you can; it capitalises and grows at your rate otherwise.
- IDR plans make sense for low earners — run the payment both ways before choosing.
Frequently asked questions
How long does it take to pay off student loans?
Standard repayment is 10 years (120 monthly payments). Extended plans stretch 25-30 years, and income-driven plans forgive the remainder after 20-25 years of qualifying payments. This calculator models the exact monthly payment for any term you enter.
Should I consolidate or refinance my student loans?
Federal consolidation combines loans into one payment without changing the rate — often worth it for simplicity. Private refinancing can cut the rate but moves the loan out of federal protections (IDR, forbearance, forgiven balances). Only refinance the federal portion when you are sure you will not need those safety nets.
What happens if I pay more than the minimum?
The extra goes to principal, cutting total interest and shortening the term — both shown in the schedule. Because interest is front-loaded, early extra payments do the most work.
How is student loan interest calculated?
Daily, on the current principal balance (federal loans use a daily-rate formula). During in-school and grace periods, subsidized loans ignore interest while unsubsidized loans accrue it, which then capitalises into your balance at repayment — another reason to pay it early if you can.