Loan Calculator
Enter the amount you want to borrow, the term, the interest rate and how often you will pay. You get the size of each payment, the total you will repay and the interest you will pay.
Created by the Reeliy Editorial Team. Last updated: Oct 19, 2026
How to use the loan calculator
- Loan amount: the principal you borrow, at least 1.
- Loan term: how long you have to repay, in years, half-years, quarters, months or days.
- Interest Rate (APR): the nominal yearly rate, in percent, from 0.1 upward.
- Compound frequency: how often unpaid interest is added to the balance. Monthly is the default.
- Pay Back: how often you make a payment, from every year to every day.
The results show the size of each payment, the total payments (the payment times the number of payments) and the total interest (total payments minus the amount borrowed). The term must be greater than zero.
The calculator assumes a fixed rate, equal payments and no fees, insurance or early-repayment charges. Real loan offers can differ, so use it for comparison and planning.
The mathematics of paying a loan back
A standard installment loan is repaid with equal payments. Each payment first covers the interest that has built up since the previous one, and what is left reduces the balance. Early payments are mostly interest; later ones are mostly principal. The payment that retires a loan of L over n payments at a rate of i per payment period is:
payment = L × i ÷ (1 − (1 + i)−n)
The rate per payment period depends on how the interest compounds. When it compounds at least as often as you pay, the calculator converts the annual rate into the equivalent rate for one payment period: i = (1 + APR ÷ m)m ÷ p − 1, where m is the number of compounding periods a year and p is the number of payments a year. When you pay more often than interest compounds, the payments made within a compounding period are pooled and applied together at its end, so the borrower gets no interest credit until then.
Example. Borrow $10,000 for 5 years at 6% APR, compounded monthly and repaid monthly. The rate per month is 6% ÷ 12 = 0.5%, and there are 60 payments:
payment = 10,000 × 0.005 ÷ (1 − 1.005−60) = 50 ÷ 0.258628 = $193.33
Over 60 payments that adds up to $11,599.68, so the interest cost is $1,599.68. The first three payments split like this:
| Payment | Interest | Principal | Balance after |
|---|---|---|---|
| 1 | $50.00 | $143.33 | $9,856.67 |
| 2 | $49.28 | $144.04 | $9,712.63 |
| 3 | $48.56 | $144.76 | $9,567.86 |
Each month's interest is the previous balance times 0.5%. As the balance falls, the interest share shrinks and the principal share grows, even though the payment never changes.
How term, rate and payment frequency change the cost
A longer term lowers the payment but raises the total interest, because the balance stays outstanding for longer. A higher rate does the same. These tables use a $10,000 loan with monthly compounding and monthly payments:
| Term | Monthly payment | Total interest |
|---|---|---|
| 3 years | $304.22 | $951.90 |
| 5 years | $193.33 | $1,599.68 |
| 7 years | $146.09 | $2,271.19 |
| 10 years | $111.02 | $3,322.46 |
| APR | Monthly payment | Total interest |
|---|---|---|
| 4% | $184.17 | $1,049.91 |
| 6% | $193.33 | $1,599.68 |
| 8% | $202.76 | $2,165.84 |
| 10% | $212.47 | $2,748.23 |
The frequency of payments matters too. Paying more often reduces the balance sooner, so less interest builds up. For the same $10,000 over five years at 6% compounded monthly:
| Pay back | Each payment | Total payments |
|---|---|---|
| Every year | $2,384.81 | $11,924.05 |
| Every 6 months | $1,174.56 | $11,745.65 |
| Every quarter | $582.89 | $11,657.78 |
| Every month | $193.33 | $11,599.68 |
Loan basics for borrowers
Before you compare offers, it helps to know the vocabulary.
Secured and unsecured loans
A secured loan is backed by an asset, such as a car or a home, that the lender can take if you stop paying. Because the lender carries less risk, the rate is usually lower. An unsecured loan has no collateral, so the lender relies on your credit record and income, and charges more for it.
Fixed and variable rates
A fixed rate stays the same for the life of the loan, which keeps payments predictable. A variable rate follows a benchmark and can move up or down, so payments can change. This calculator assumes a single fixed rate.
APR and compounding
The APR entered here is the nominal yearly rate. How often that interest compounds changes the cost a little, and in this calculator the cost is lowest when compounding matches your payment schedule. For a five-year, $10,000 loan at 6% repaid monthly, total interest is $1,599.68 with monthly compounding, $1,603.74 with daily compounding, $1,649.15 with quarterly compounding and $1,869.82 with annual compounding. The coarser conventions cost more because payments made during a compounding period are applied only at its end. Ask your lender which convention applies to a real offer.
Term and extra payments
Choose the shortest term whose payment you can comfortably afford. If a loan permits it, paying extra toward the principal cuts the interest, because every dollar of principal repaid early stops accruing interest for the remaining months.
Keep in mind
Compare total payments as well as the monthly figure: a low payment on a long term can hide a high total cost. For other borrowing and saving questions, see the compound interest calculator.
Results are estimates, not a loan offer or financial advice. Your lender's schedule, fees and rounding will differ. See our disclaimer.
Frequently asked questions
How is the loan payment calculated?
The payment is the loan amount times the periodic rate, divided by one minus the periodic growth factor raised to the negative number of payments. The result keeps every payment equal while paying off the whole balance by the end of the term.
Why is total interest higher on a longer loan even though the payment is lower?
A longer term leaves more principal outstanding for more months, so interest accrues for longer. The smaller payment spreads the same debt out, but you pay interest on it for more periods.
Does compounding frequency change my payment?
Yes, a little. In this calculator the payment is lowest when compounding matches your payment schedule. Compounding more often than you pay adds a small amount of interest, and compounding less often than you pay raises the payment more noticeably, because payments within a compounding period are applied only at its end. For $10,000 over five years at 6% repaid monthly, the payment is $193.33 with monthly compounding, $193.40 with daily compounding and $197.83 with annual compounding.
Does this include fees or insurance?
No. It covers interest and principal only, so origination fees, insurance and other charges would add to the real cost.
References
- Kellison, The Theory of Interest, McGraw-Hill
- Consumer Financial Protection Bureau, consumer education material on loans and APR
Cite this calculator and page
If you use this page in your work, you can cite it as:
Reeliy Editorial Team. (2026). Loan Calculator. Reeliy. https://reeliy.com/calculators/loan-calculator“Loan Calculator.” Reeliy, 2026, https://reeliy.com/calculators/loan-calculator.