Finance & business
Loan Calculator
A fixed monthly loan payment uses the formula M = P · i(1+i)ⁿ ÷ ((1+i)ⁿ − 1), where P is the amount borrowed, i is the monthly rate (annual rate ÷ 12), and n is the number of payments. Enter your loan to see the payment, the full amortization schedule, your payoff date — and exactly how much interest and time an extra payment saves you.
Pick a loan type to load typical defaults, then adjust. Add an extra monthly payment or switch to biweekly to watch the interest and payoff date drop in real time. It runs entirely in your browser, shows the exact amortization math, and lets you download the full schedule.
Loan details
per month
Assumes a fixed rate and equal payments. Fees, insurance and rate changes aren't included.
Your early-payoff savings
Add an extra payment above to see your savings.
How your balance falls
Your loan balance over time. When you add extra payments, the orange line drops faster — the gap between the lines is the time you save.
Amortization schedule
Every payment split into principal and interest, with the remaining balance. Early payments are mostly interest; later ones mostly principal.
| Year | Principal | Interest | Balance |
|---|---|---|---|
| Enter your loan to see the schedule. | |||
How the loan calculator works
This tool uses the standard amortization formula — the same math U.S. lenders use for fixed-rate auto, personal, student and home loans. Each month you pay the same amount; early payments are mostly interest and later payments mostly principal, but the monthly figure stays constant unless you pay extra.
monthly payment formula
M = P × i(1 + i)ⁿ ÷ [ (1 + i)ⁿ − 1 ]where: P = principal (loan amount) i = monthly interest rate = annual rate ÷ 12 ÷ 100 n = number of monthly payments = term in years × 12 (when i = 0, the payment is simply P ÷ n)
To build the schedule, each month the interest is balance × i, the principal portion is payment − interest, and the balance falls by that principal. Any extra payment goes straight to principal, which shrinks the balance faster and cuts the interest on every remaining month — that compounding is why a small extra amount saves so much.
Biweekly payments
The "accelerated biweekly" plan models the popular strategy of paying half your monthly amount every two weeks. Because there are 26 two-week periods in a year, you make the equivalent of 13 monthly payments instead of 12 — one extra payment a year — which this tool applies as an extra 1/12 of your payment each month. Confirm your lender applies biweekly payments to principal immediately rather than holding them.
Notes & assumptions
- Assumes a fixed interest rate for the entire term and equal payments.
- Does not include arrangement fees, insurance, taxes or early-repayment penalties — check your loan agreement.
- Paying extra reduces the term, not the required monthly payment, unless your lender recasts the loan.
- Calculations are for general information only — verify with your lender before relying on them.
Worked example
A $25,000 auto loan at 7% over 5 years (60 months) has a monthly payment of about $495.03, with roughly $4,702 in total interest. Add $100 a month and you pay it off about 11 months early and save close to $940 in interest — because every extra dollar of principal stops accruing interest for the rest of the loan. Change any input above and the payment, schedule, chart and savings all recalculate instantly.
Frequently asked questions
How much can I save by paying extra on my loan each month?
It depends on your balance, rate and how much extra you pay, but the savings are often larger than people expect because each extra dollar of principal removes interest from every remaining month. Enter an extra amount above and the calculator shows your exact interest saved, months saved and new payoff date. As a rule of thumb, higher rates and earlier extra payments save the most.
Do biweekly payments really pay off a loan faster?
Yes. Paying half your monthly amount every two weeks means 26 half-payments a year, which equals 13 full monthly payments instead of 12 — one extra payment annually. That single extra payment each year can shave months or years off the term and save meaningful interest. Just confirm your lender applies the payments to principal right away and doesn't charge a fee to set it up.
Is it better to make extra monthly payments or one big lump sum?
Both help, and the math rewards whichever puts money toward principal sooner. A lump sum early in the loan removes interest from the most remaining months, so it can save more than the same total spread out later. Steady extra monthly payments are easier to sustain and still save a lot. The best choice is usually whichever you'll actually stick to.
How do I calculate my loan payoff date?
The payoff date is your loan's start date plus the number of monthly payments. A 5-year loan started today is paid off in 60 months; extra payments shorten that. This calculator shows the payoff date for both the standard schedule and your accelerated plan, so you can see exactly when you'd be debt-free.
Does paying extra lower my monthly payment or shorten the term?
It shortens the term. Your required monthly payment stays the same; the extra goes straight to principal, so you finish the loan sooner and pay less total interest. If you specifically want a lower monthly payment, you'd need your lender to "recast" the loan after a large principal payment, or refinance — that's a different process.
Why is most of my early loan payment going to interest?
Interest is charged on the outstanding balance, which is highest at the start. So early on, a large share of each payment covers interest and only a little reduces principal. As the balance falls, the interest portion shrinks and more of each payment goes to principal — which is why the amortization schedule above shows the split flipping over time.
What's the difference between APR and the interest rate?
The interest rate is the cost of borrowing the principal alone. The APR folds in certain lender fees and points, so it's usually a little higher and reflects a truer all-in cost. When comparing loan offers in the U.S., the APR gives a more apples-to-apples comparison because the Truth in Lending Act requires lenders to disclose it.