Loan Calculator
This free loan calculator estimates your monthly payment for an auto, personal, or other general loan from the loan amount, interest rate, and term in months. It also shows total interest paid, total cost, and payoff date, plus how much an optional extra monthly payment would save. Nothing you enter is sent anywhere or stored.
How to Use It
- Enter the loan amount, interest rate, and loan term in months.
- Optionally add an extra monthly payment to see how much it saves.
- Your monthly payment, total interest, total cost, and payoff date update instantly, along with a month-by-month remaining balance table.
How It Works
Monthly payment is calculated with the same standard loan amortization formula used for mortgages, spreading the loan amount evenly over every monthly payment so that, by the final payment, the loan is fully paid off. If you set an extra monthly payment, that required payment doesn't change. Instead, the extra amount goes straight toward the remaining balance each month, which shortens the loan and reduces total interest, tracked month by month rather than read off a single formula, since the payoff date itself moves once extra payments are involved.
Formula
monthly payment = loan amount × [r(1 + r)^n] ÷ [(1 + r)^n − 1], where r = annual rate ÷ 12 ÷ 100 and n = number of monthly payments
A worked example: a $25,000 loan at 6% annual interest over 60 months comes to a required monthly payment of $483.32, with $3,999.20 in total interest over the full 60 months, for a total cost of $28,999.20. Add a $50 extra payment each month, and the required payment stays $483.32, but the loan is paid off in 54 months instead of 60, with total interest dropping to $3,558.29, a savings of $440.91.
The month-by-month remaining balance table shows this directly: with the extra payment, the balance reaches zero six months sooner than the entered term, and the table's final row reflects that actual payoff month rather than the original 60-month schedule.
Everything runs client-side in your browser. No numbers you enter are sent anywhere or stored.
Frequently Asked Questions
What does "monthly payment" mean here, and why doesn't it change when I add an extra payment?
It's the required minimum payment, calculated from the loan amount, interest rate, and term you enter, the same figure a lender would quote you. Adding an extra monthly payment doesn't lower that required amount. It goes entirely toward paying down the balance faster, which shortens the loan and reduces total interest instead of reducing what you owe each month.
How much can extra payments really save me?
It depends on the loan amount, rate, and how early the extra payments start, but the effect compounds. On a $25,000 loan at 6% over 60 months, an extra $50 a month pays the loan off 6 months early and saves $440.91 in interest, without changing the required monthly payment at all. See the worked example below for the full math.
Why does this calculator ask for the loan term in months instead of years?
Auto and personal loans are conventionally quoted in months (36, 48, 60, 72), not whole years, since terms often fall between year marks. This is different from a mortgage, which almost always uses whole-year terms. That's why the Mortgage Calculator uses a year selector and this one uses a plain months field.
How is this different from the Mortgage Calculator?
The math is the same standard loan amortization formula, but this tool is built for general loans (auto, personal, and similar) rather than home loans specifically. It leaves out mortgage-only items like a down payment, property tax, home insurance, HOA fees, and PMI, none of which apply to a typical auto or personal loan.
What is and is not included in the total cost of the loan?
Total cost here is the loan amount plus total interest paid, nothing else. It doesn't include lender fees, origination charges, taxes, title or registration costs, or any add-on products a dealer or lender might offer, since none of those are part of the loan math itself and they vary by lender and situation. Ask your lender for the full cost breakdown of an actual offer.
Does a lower interest rate always mean a smaller total cost?
For the same loan amount and term, yes. A lower rate directly reduces the interest charged on whatever balance remains each month, which lowers both the required payment and the total interest paid over the life of the loan. Shortening the term has a similar effect, for the same reason a 15-year mortgage costs less in total interest than a 30-year one at the same rate.
Is this a loan offer or a guaranteed rate?
No. This is a planning estimate based on the numbers you enter, not a loan offer, pre-approval, or rate quote. Your actual rate, term, and payment depend on the lender, your credit, and the specific loan product, so treat this as a way to compare scenarios before you talk to a lender, not as a substitute for a real quote.