Finance & business
Loan Calculator
Enter your loan amount, annual interest rate and term to see your fixed monthly payment, the total interest you'll pay, and the total you'll repay. Whether you're sizing up an auto loan, a personal loan, a student loan refinance or a small-business note, this calculator helps you compare offers before you sign. In the United States, lenders quote rates as an annual percentage and bill you monthly, so seeing the per-month figure alongside the lifetime interest makes it easy to judge whether a longer term is really saving you money. It updates as you type, runs entirely in your browser, and shows the exact formula below.
Loan details
per month for the full term
Assumes a fixed rate and equal monthly payments. Fees, insurance and rate changes are not included.
How the loan calculator works
This tool uses the standard amortization formula — the same math U.S. lenders use for fixed-rate loans. Each month you pay the same amount; early payments are mostly interest and later payments are mostly principal, but the monthly figure stays constant.
monthly payment formula
Payment = P × r × (1 + r)ⁿ ÷ [ (1 + r)ⁿ − 1 ]where: P = principal (loan amount) r = monthly interest rate = annual rate ÷ 12 ÷ 100 n = number of monthly payments = term in years × 12
Total paid is simply monthly payment × n, and total interest is total paid − principal. When the interest rate is 0%, the formula reduces to P ÷ n.
Notes & assumptions
- Assumes a fixed interest rate for the entire term and equal monthly payments.
- Does not include arrangement fees, insurance, taxes or early-repayment charges.
- Calculations are for general information only — verify with your lender before relying on them.
Worked example
Say you take out a $25,000 used-car loan at a 7.5% annual interest rate over a 5-year (60-month) term. The monthly rate is 7.5 ÷ 12 ÷ 100 = 0.00625, and the formula returns a fixed payment of about $500.76 per month. Over the full 60 payments you'd repay roughly $30,046, of which about $5,046 is interest. Stretch the same loan to a 7-year term and the monthly payment drops to around $382, but the total interest climbs past $7,000 — a useful reminder that a lower monthly payment usually costs more in the long run.
Frequently asked questions
How is my monthly loan payment calculated?
Your payment comes from the standard amortization formula, which spreads the principal and interest evenly across every month of the term. It uses three inputs — the amount you borrow, the monthly interest rate (the annual rate divided by 12), and the total number of payments. The math keeps the monthly amount constant, but the split shifts over time: early payments are mostly interest, while later ones go mostly toward principal.
What's the difference between APR and the interest rate?
The interest rate is the cost of borrowing the principal alone. The APR (annual percentage rate) folds in certain lender fees and points, so it's usually a little higher and gives you a truer all-in cost. When you compare loan offers in the U.S., the APR is the better number for an apples-to-apples comparison because the Truth in Lending Act requires lenders to disclose it.
What's the difference between a fixed and a variable rate?
A fixed rate stays the same for the entire term, so your payment never changes — that's what this calculator assumes. A variable (or adjustable) rate can move up or down with a benchmark index, which means your payment and total interest can change over time. Variable rates often start lower but carry the risk of rising later.
Does this calculator include taxes and insurance?
No. This tool covers only principal and interest. For a home loan, your real monthly bill typically also includes property tax, homeowners insurance and sometimes mortgage insurance held in escrow — for those, use our mortgage calculator. Auto and personal loans may also add fees or optional protection products that aren't shown here.
How can I lower my monthly payment?
You can reduce the monthly amount by borrowing less, securing a lower interest rate (often through a stronger credit score or a co-signer), or choosing a longer term. Keep in mind that a longer term lowers the monthly payment but increases the total interest you pay. Making extra payments toward principal, or refinancing when rates drop, are other common ways to cut the overall cost.