Free Online Calculators
Monthly payment, payoff date & balance chart โ annuity formula
This loan calculator works out your monthly payment, total payoff date, and plots a running balance chart so you can see exactly how your debt decreases over time. It uses the standard annuity formula, where each payment covers both interest and a portion of the principal. Just enter your loan amount, interest rate, and term to get instant results.
Whether you're financing a new car, buying your first home, or consolidating debt, understanding exactly what a loan will cost you โ month by month โ is one of the smartest financial moves you can make. Our free Loan Calculator takes three simple inputs and instantly shows your monthly payment, your total interest paid over the life of the loan, and a full amortization overview so you can see your balance shrinking in real time. No spreadsheets, no financial jargon, no guesswork โ just clear, accurate numbers you can act on right now.
The monthly payment figure is calculated using the standard annuity formula, which is the same method banks and lenders use when they quote you a payment amount. Here's what it looks like:
M = P ร [r(1 + r)n] รท [(1 + r)n โ 1]
Because the formula accounts for compound interest, every payment you make covers both the interest that has accrued since your last payment and a portion of the remaining principal. Early in a loan, most of your payment goes toward interest. As the balance falls, more and more of each payment chips away at the principal โ a process called amortization. Our calculator maps this entire journey for you, so you can see at any point in the loan how much you still owe and how much of your money has gone to interest versus principal reduction.
Type in the total amount you plan to borrow โ the principal. This is the purchase price minus any down payment, or the full balance if you're refinancing. For example, if you're buying a $25,000 car and putting $5,000 down, your loan amount is $20,000.
Input the annual percentage rate (APR) your lender has quoted you. Enter it as a percentage โ for instance, type 6.5 for a 6.5% rate. The calculator automatically converts this to a monthly rate by dividing by 12, which is exactly what the formula requires.
How long do you have to repay the loan? Enter the total number of months. Common terms include 36 months (3 years), 60 months (5 years), 84 months (7 years) for auto loans, and 180 or 360 months (15 or 30 years) for mortgages.
Hit the calculate button and the results appear instantly. You'll see your fixed monthly payment, the total amount you'll pay over the life of the loan, and the total interest โ which is simply the total paid minus the original principal. The amortization overview lets you see your outstanding balance at any stage of repayment.
The real power of the calculator is comparison. Try increasing your down payment to see how it lowers monthly payments. Shorten the term and watch how much interest you save overall. Run the numbers on two competing loan offers side by side. A small difference in interest rate can mean thousands of dollars over a long-term loan.
You want to buy a used car priced at $15,000. A dealership offers you a 60-month loan at 7.9% APR. Plugging those numbers in: your monthly payment comes out to approximately $303. Over 60 months, you'll pay a total of around $18,180 โ meaning you'll pay roughly $3,180 in interest on top of the car's price. Knowing this upfront helps you decide whether to negotiate a lower rate, make a larger down payment, or choose a shorter term.
You're renovating your kitchen and need $10,000. Your bank approves a 36-month personal loan at 11% APR. The calculator shows a monthly payment of about $327. You'll repay a total of roughly $11,772 โ paying $1,772 in interest over three years. Compare that to a 60-month version of the same loan: the monthly payment drops to about $217, but your total interest nearly doubles to around $3,020. The side-by-side comparison makes the trade-off crystal clear.
You're purchasing a home with a $300,000 mortgage at 6.75% APR over 360 months (30 years). The monthly payment is approximately $1,945. Over 30 years, you'll pay roughly $700,200 in total โ meaning $400,200 goes to interest alone. That's a striking number, and it perfectly illustrates why many homeowners choose to make extra principal payments when possible. Run the same loan as a 15-year mortgage at the same rate and the monthly payment jumps to about $2,656 โ but your total interest drops to around $178,000, saving you over $220,000.
The interest rate is the base cost of borrowing the principal, expressed as a percentage. The Annual Percentage Rate (APR) includes the interest rate plus any additional fees or costs โ like origination fees โ rolled into a single annual figure. For this calculator, use the APR when it's available, as it gives you a more complete picture of the true cost of the loan. If your lender only quotes a simple interest rate, use that, but be aware the actual cost may be slightly higher once fees are factored in.
Yes, significantly. The annuity formula calculates payments assuming you pay exactly the scheduled amount each month with no extra contributions. If you make additional principal payments โ even small ones โ you'll pay off the loan faster and reduce the total interest you owe. While our calculator shows the standard amortization schedule, you can use the results as a baseline and then experiment: calculate how much total interest you'd pay normally, then mentally compare it to what an extra $50 or $100 per month would accomplish over the life of your loan.
Small differences can arise from a few sources. Some lenders charge fees that are baked into your payment. Others use slightly different rounding conventions, or they might calculate interest on a daily basis rather than monthly. Additionally, the first payment date and the loan origination date can create a partial-month interest charge that shifts the numbers slightly. Our calculator uses the standard annuity formula and monthly compounding, which matches the vast majority of consumer loans โ so any difference should be minimal and easily explained by your lender.