How to use the student loan payoff calculator
- Enter the loan balance and the interest rate from your servicer.
- Choose how your payment is set. For the standard plan, enter the repayment term in years and months. If you already know your payment, choose that option and enter the amount.
- Enter an extra monthly payment to see the effect, and under More options add any unpaid interest that will be added to the balance.
- Read the payoff time, total interest and what the extra payments save. The comparison table shows several extra amounts side by side, and the CSV has every month.
Formula
Monthly rate r = APR / 12; number of payments n = years x 12 + months
Payment = L x r / (1 - (1 + r)^-n), rounded to the cent
Each month: interest = remaining balance x r (rounded to the cent); the rest of the payment, plus any extra, reduces the balance
Final payment = remaining balance + that month's interest
This is the standard fixed-payment calculation. If you enter a known payment instead of a term, the loan simply runs until the balance reaches zero. Unpaid interest that is capitalized is added to the starting balance.
Worked example: $32,000 at 5.5% over 10 years
The standard payment on $32,000 at 5.5% for 120 months is $347.28. Paying only that amount costs $9,674.30 in interest, so you repay $41,674.30.
Adding $100 a month raises the payment to $447.28 and ends the loan after 87 payments (7 years 3 months), which is 33 months sooner. Total interest falls to $6,866.62, saving $2,807.68.
Other extra amounts: $25 a month means 110 payments and $901.66 saved, $200 means 69 payments and $4,338.23 saved, and $500 means 42 payments and $6,455.90 saved. If you already pay $350 a month and no extra, the loan lasts 119 payments and costs $9,567.18 in interest.
What this calculator covers
It models standard repayment of one loan at one fixed rate, which is how many private loans and the federal Standard Repayment Plan work. Federal loans also offer other plans. See Federal Student Aid for the plans and for your own loan details.
Income-driven repayment plans are not modeled. Those plans set the payment from your income and family size, can change every year, may leave a balance that is later forgiven under program rules, and may let unpaid interest grow. This tool cannot represent that, so do not use its payoff date for an income-driven plan.
How extra payments help
Every extra dollar that goes to principal stops accruing interest for the rest of the loan. The earlier you pay, the more it saves. Ask your servicer how extra payments are applied. Some apply them to the next due date instead of principal unless you give instructions, and some target the loan with the highest rate when you hold several loans.
With multiple loans at different rates, run each one on its own. Averaging the rates hides the fact that paying the highest-rate loan first saves the most. The debt payoff calculator compares paying order for up to six debts.
Unpaid interest and capitalization
If interest builds up before repayment starts, for example during school or a deferment, some loans add it to the principal when repayment begins. That raises the balance that earns interest. Enter that amount in More options and the calculator starts from the larger balance. For other fixed-rate loans, the loan calculator works the same way, and the interest rate calculator can recover a rate from a payment.
Assumptions and limits
- One loan, one fixed rate and equal monthly payments made at the end of each month.
- Interest each month is the balance times APR / 12, rounded to the cent. Servicers that accrue interest daily may differ by small amounts.
- Extra money is applied entirely to principal every month, starting with the first payment.
- Income-driven plans, forgiveness, deferment, forbearance, rate changes and rate discounts are not modeled.
- The default rate and balance are example values. Use the figures on your loan statement.
- This is an estimate for planning, not financial advice. Your servicer's figures control.
Frequently asked questions
How long will it take to pay off my student loan?
Under standard repayment it takes the term you choose, such as 120 months for 10 years. Extra payments shorten it: $100 more a month on a $32,000 loan at 5.5% finishes in 87 months instead of 120.
Is it better to pay extra or invest?
That depends on your loan rate, expected returns, taxes and risk comfort, which this tool does not model. It shows the guaranteed interest saved by paying extra, so you can weigh it against alternatives.
Does this work for federal student loans?
It works for the standard fixed-payment case, including federal loans on a standard plan. It does not model income-driven plans, forgiveness, deferment or forbearance, so confirm those details with your servicer.
What does unpaid interest added to the balance mean?
Interest that accrued but was not paid can be added to the principal at some points, such as the start of repayment. The new, larger balance then earns interest. Enter that amount in More options to include it.
Why enter my current payment instead of a term?
Your actual payment may not match a standard term, for example after a refinance or when you already pay extra. Entering it shows how long that exact payment takes, and the extra field lets you test adding more.