Loan calculator (student and other loans)
Works for any loan with a fixed payment: student, business, from a relative, an appliance. Enter amount, rate and term, then add an extra payment to see how much interest you save and how many months sooner you finish.
Applied to principal every month.
- Total interest
- $4,046
- Total repaid
- $24,046
Amortization schedule
| Month | Payment | Interest | Principal | Balance |
|---|---|---|---|---|
| 1 | $400.76 | $125.00 | $275.76 | $19,724.24 |
| 12 | $400.76 | $105.44 | $295.32 | $16,574.74 |
| 24 | $400.76 | $82.51 | $318.25 | $12,883.56 |
| 36 | $400.76 | $57.80 | $342.95 | $8,905.84 |
| 48 | $400.76 | $31.18 | $369.58 | $4,619.31 |
| 60 | $400.76 | $2.49 | $398.27 | $0.00 |
Save this calculation and follow your plan
In the Boosteate app your cards, loans and banks connect on their own: you will see the real APR, the minimum payment and a plan to get out of debt with your numbers, not examples.
Join the waitlistHow it is calculated
The base payment uses the standard amortization formula (constant payment). With an extra payment the schedule is recalculated month by month: the extra goes entirely to principal, so the next month’s interest is lower and the loan ends sooner.
The amortization schedule shows, per month, how much goes to interest, how much to principal and the remaining balance. The final payment is adjusted so the balance closes at exactly zero.
Frequently asked questions
How do I model a federal student loan here?
The standard plan is 10 years with a fixed payment: enter the balance, your loans’ rate (or the weighted average) and 120 months. Income‑driven plans do not have a fixed payment and are not modeled by this tool.
Is the extra payment worth it?
Almost always, as long as you have no more expensive debt (credit cards) and keep an emergency fund. An extra $50 on a $20,000 loan at 7.5% over 5 years saves about $260 in interest and finishes 5 months early.
Do biweekly payments help?
Paying half the monthly payment every two weeks equals 13 payments a year instead of 12: it works like one extra payment a year and shortens the term. Simulate it by entering the payment divided by 12 as the monthly extra.
These calculators are educational estimates based on the numbers you enter; they are not a credit offer nor financial, legal or tax advice. Reference rates are reviewed yearly.