Free simple loan calculator: three inputs give you the payment, total interest, and payoff date for any fixed-rate loan, no sign-up.
Defaults to this month.
Try the $10,000 exampleSwitch to simple interestTry 60 months
Estimates only. Your lender's statement is the number that counts. Read how we calculate.
Three numbers in, one payment out. The schedule below is here if you want it, and the simple-interest mode is for loans that accrue interest daily.
Enter the amount, rate, and term in months; the payment, total interest, and payoff date update as you type. Switch to Simple interest if your contract accrues interest daily, and open Options for a start date or an extra monthly amount. The full schedule is below the chart.
The payment uses the standard amortization formula, M = P × i ÷ (1 − (1 + i)−n), with i the annual rate divided by 12 and n the number of months (Calculator.net loan calculator, amortization schedule, Wikipedia). Each month, interest is the balance times i, the rest of the payment reduces the balance, and the loop ends when the balance is zero.
Simple interest (daily accrual) keeps the same payment but computes each period's interest as the balance times the annual rate divided by 365 times the days in the period, either 30 or the actual calendar days. Because interest is charged only on what is owed for the days it is owed, paying early or extra reduces it immediately. Many auto loans and some personal loans work this way; the total comes out close to the amortized figure, a little lower or higher depending on the calendar.
The flat comparison line is principal times rate times years. Some short-term and informal loans charge interest that way, but a normal installment loan does not, so the page shows it only as a contrast.
APR versus interest rate. The rate sets the interest here. APR includes certain fees and is usually slightly higher; use it to compare offers, not to fill in this calculator.
| Amortizing | Simple interest, 30-day months | |
|---|---|---|
| Monthly payment | $318.00 | $318.00 |
| Payments | 36 | 36 |
| Total interest | $1,447.90 | $1,424.33 |
| Total repaid | $11,447.90 | $11,424.33 |
| Flat comparison (not how installment loans work) | $2,700.00 | $2,700.00 |
Cedrick Reese built this calculator. The amortizing case uses the standard amortization formula, whose $250,000 base case matches figures published by several independent calculators to the cent. The simple-interest mode uses a 365-day daily rate on the outstanding balance, which is how that kind of contract accrues, and the flat line is shown only so the difference is visible. No live rate data is used. Report any mismatch with a lender's schedule through the contact page.
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For an amortizing loan, the monthly payment is M = P × i ÷ (1 − (1 + i) to the power of minus n), where P is the amount, i is the annual rate divided by 12, and n is the number of months. On $10,000 at 9% for 36 months that gives $318.00. If the rate is zero, the payment is just the amount divided by the months.
Both charge interest only on what you still owe. An amortizing loan computes it once a month on the balance. A simple-interest loan accrues it daily, so the exact interest in a period depends on the days between payments. The payment is usually set the same way; the difference shows up in total interest and in how much paying early helps.
Lenders set the payment with the amortization formula regardless of how interest accrues. In simple-interest mode the interest per period is computed on a 365-day daily rate rather than a 12-period monthly rate, so it comes out slightly different, and the final payment absorbs the difference. On the $10,000 example the gap is about $24 over three years.
Add up the interest column of the schedule, or take total repaid minus the amount borrowed. On $10,000 at 9% for 36 months the amortized total is $1,447.90. The flat figure of $2,700 you get from principal times rate times years is not how installment loans work, because it ignores the balance falling as you pay.
The interest rate is what the lender charges on the balance and is what this calculator uses. APR folds in certain fees, such as an origination fee, so it is usually a little higher and is the better number for comparing offers. If a lender quotes only an APR, the schedule here will run slightly high on interest.
Yes, for any fixed-rate loan with equal monthly payments. Use amortizing mode unless your contract says interest accrues daily, which is common on auto loans and some personal loans; then use simple interest. Loans with variable rates or balloon payments need a different tool.