Private Student Loan Calculator
What this calculator does
Private student loans work differently from federal loans: they carry origination fees, credit-based rates, and in-school repayment choices that change what you ultimately pay. This calculator builds the true cost of a private loan from your inputs: the loan amount, the origination fee, the APR, the term, and what you do while in school.
Choose immediate repayment, interest-only payments while in school, or full deferment, and the tool shows your monthly payment, the interest that accrues or capitalizes before repayment starts, total interest, and total cost. Zero percent APR is handled correctly as a valid input.
Private Student Loan Calculator
True cost with origination fees and in-school repayment options.
Shows your new payoff date and interest saved.
Origination fees are added to the amount borrowed. Deferred interest capitalizes (compounds) into the balance; interest-only payments keep the balance flat. Standard amortization; 0% APR is valid. Educational estimate, not lending advice.
Worked example
Borrow $30,000 with a 2% origination fee at 6.5% APR for 10 years, repaying immediately:
- Origination fee: 30,000 x 0.02 = $600.00; starting principal = $30,600.00
- Monthly rate: 0.065 / 12 = 0.00541667; payments: 120
- Monthly payment: 30,600 x (0.00541667 x 1.00541667120) / (1.00541667120 – 1) = $347.46
- Total paid: 347.46 x 120 = $41,694.82; total interest = 41,694.82 – 30,600 = $11,094.82
Choose full deferment for 48 months instead: the $30,600 balance compounds to 30,600 x 1.0054166748 = $39,658.23, and the payment becomes $450.31 a month. Deferment costs an extra $9,058.23 in capitalized interest before repayment even starts.
Add an extra $100 a month to the base example: the loan is paid off in 86 payments (7 years 2 months) instead of 120, and total interest drops from $11,094.82 to $7,727.24, a saving of $3,367.58. Enter any extra amount in the calculator to see your own payoff date and savings. Enter these numbers and the calculator reproduces every figure.
What the in-school options really do
The old version of this page showed a repayment-option dropdown that the calculator ignored. This rewrite implements all three honestly. Immediate repayment starts the amortization clock at disbursement, so interest never gets a chance to compound unpaid. Interest-only payments while in school keep the balance flat at the starting principal: you pay principal x monthly rate each month, which avoids capitalization but still costs cash during school. Full deferment lets unpaid interest compound into the balance, so you repay interest on interest later. Deferment feels cheapest in school and is the most expensive over the life of the loan.
Origination fees: the cost most estimators skip
Many private lenders charge an origination or disbursement fee, often 0 to 5% of the loan, which is added to your balance. A 2% fee on $30,000 is $600 of extra principal that accrues interest for the full term. At 6.5% over 10 years that $600 costs about $218 in additional interest, so the fee’s true price is roughly $818, not $600. Always compare loans on the fee-inclusive principal, not the sticker amount.
Fixed versus variable rates, and the cosigner question
Private loans come in fixed and variable flavors. A fixed rate never moves, so your payment is predictable for the whole term. A variable rate starts lower but follows a benchmark, so payments can rise; a variable quote should be stress-tested at 2 to 3 points above the starting rate before you sign. Most undergraduates need a cosigner to qualify for competitive private rates. A cosigner is equally liable for the debt, and many lenders offer cosigner release after 24 to 48 on-time payments, but the criteria are strict and far from automatic, so read the release terms before counting on them.
Private versus federal loans at a glance
- Rates: federal rates are fixed by Congress each year; private rates are credit-based and can be fixed or variable
- Fees: federal loans carry a disbursement fee near 1%; private origination fees run 0 to 5%
- Repayment flexibility: federal loans offer income-driven plans, deferment, and forbearance by law; private options are whatever the contract says
- Forgiveness: federal loans may qualify for Public Service Loan Forgiveness and other programs; private loans are never forgiven by the government
- Borrowing rule of thumb: exhaust federal Direct loans first every year, then fill the remaining gap with private loans only if needed
What competing private-loan calculators miss
EmergencyFundCalculator has a grace period and a federal-versus-private comparison, and OnlyCalculators adds an extra-payment option with a chart. But most private-loan calculators ignore origination fees entirely, treating the borrowed amount as the starting balance, and few model interest-only versus deferred in-school repayment. This calculator starts from the true principal (amount plus fee), models all three in-school options with capitalized interest, and now shows the extra-payment payoff date and interest saved.
Frequently asked questions
How is a private student loan different from a federal loan?
Private loans are made by banks and lenders with credit-based rates that can be fixed or variable, origination fees of 0 to 5 percent, and repayment terms set by the contract. Federal loans have Congressionally set fixed rates, standardized fees, income-driven repayment, and access to forgiveness programs that private loans never offer.
What does an origination fee do to my loan cost?
The fee is added to your balance, so you pay interest on it for the full term. A 2 percent fee on 30,000 dollars adds 600 dollars of principal, which costs about 818 dollars total at 6.5 percent over 10 years once the interest on the fee itself is included.
Should I choose interest-only payments or full deferment while in school?
Interest-only payments keep your balance flat and avoid capitalization, so they cost less over the life of the loan. Full deferment requires no payments in school but lets interest compound into the balance, which raises both the payment and the total cost. Immediate repayment beats both if your budget allows it.
How much can extra payments save on a private student loan?
Enter any extra monthly amount and the calculator simulates the payoff: it shows the new payoff date, the interest saved, and the new total interest. On a $30,000 loan at 6.5% APR for 10 years, an extra $100 a month pays the loan off in 7 years 2 months and saves $3,367.58 in interest.
What happens with a 0% APR in this calculator?
Zero percent is treated as valid: the monthly payment is simply the principal divided by the number of payments, and total interest is zero. Many simple calculators crash or show blank results at 0 percent; this one does not.
Do I need a cosigner for a private student loan?
Most undergraduate borrowers do, because they lack the credit history and income for competitive standalone rates. A cosigner shares full legal responsibility for the debt. Some lenders offer cosigner release after 24 to 48 consecutive on-time payments, but approval is strict, so verify the exact terms before borrowing.
Is a variable rate or a fixed rate better?
A fixed rate gives a predictable payment for the whole term. A variable rate usually starts lower but can rise with its benchmark. If you consider variable, rerun the numbers at 2 to 3 points above the quoted rate: if the loan is still affordable there, the variable option is reasonably safe.
This calculator is for education only and is not lending or financial advice. Loan terms vary by lender; confirm rates, fees, and repayment options in your promissory note before borrowing.