Methodology

Common rules for every calculator

All four calculators run in your browser. What you type is not sent anywhere unless you choose to continue to the loan request form; then the estimated payment, APR and term are attached to your request.

They share these assumptions:

• Fixed rate, equal monthly payments. The interest rate is annual and is applied monthly: the monthly rate is the annual rate divided by 12.
• The payment formula. For an amount P, a monthly rate r and n months, the payment is P × r ÷ (1 − (1 + r)^−n), rounded to the cent. At a 0% rate, the payment is P ÷ n.
• A fee taken from the loan. An origination fee deducted from the loan is a prepaid finance charge. You sign for the full amount and repay it with interest, but the fee comes out first, so the amount financed (what reaches your bank account) is the loan amount minus the fee.
• APR by the actuarial method. We compute the APR the way Regulation Z’s appendix J describes for equal monthly payments: the monthly rate at which the payments are worth exactly the amount financed, times 12, shown to two decimals.
• No extra charges. The calculators leave out late fees, returned-payment fees, optional credit insurance and any other add-on unless a calculator asks for it.

Worked example

A $10,000 loan at 14% for 36 months, with a 5% origination fee taken from the loan:

Item	Amount
Monthly payment (on the full $10,000)	$341.78
Total of 36 payments	$12,304.08
Fee taken from the loan	$500.00
Deposited in your account (amount financed)	$9,500.00
Finance charge (total of payments minus amount financed)	$2,804.08
APR	17.65%

The 14% interest rate becomes a 17.65% APR because you pay interest on $10,000 but receive $9,500. These figures are an example of the math, not an offer.

The four calculators

Offer comparison calculator. For each of two offers, you enter the amount, rate, fee percentage and term. It shows the fee, the amount financed, the monthly payment, the total of payments, the finance charge, the APR and the finance charge per $100 you receive. Limits: it assumes every payment is made on time and on schedule. A lender’s own disclosure may differ by a few cents because of its payment dates or a first period that is longer or shorter than a month.

Net proceeds calculator. You enter the amount you need deposited, the fee percentage, the rate and the term. It finds the smallest whole-dollar loan amount that still leaves at least that much after the fee, then shows the fee, the deposit, the monthly payment and the APR for that amount. Limits: it covers a fee stated as a percentage of the loan. A flat fee, or a fee that is added to the balance rather than taken from it, works differently; read the lender’s disclosure.

Loan term calculator. You enter one amount and rate. It shows the payment and the total interest over 24, 36, 48, 60, 72 and 84 months. Limits: it uses the same rate for every term. In practice, lenders often price longer terms differently, and not every lender offers every term.

Extra payment calculator. You enter the balance you owe now, the rate, your monthly payment and a fixed extra amount. It runs the loan month by month: interest is charged on the balance and rounded to the cent, the payment plus the extra amount is applied, and the extra goes to principal. A balance under $1 left by rounding is cleared with the last payment. It shows how many months the loan lasts and the interest paid, with and without the extra amount. Limits: it assumes your lender applies extra money to principal right away and charges no prepayment penalty. Ask the lender how it applies extra payments before you rely on the result.

How state pages are researched

Each state rules page answers three questions: what a licensed lender may charge on a personal installment loan, who must be licensed, and where to check a lender or complain.

• Primary sources. We read the state statute and the state regulator’s own pages and cite both.
• A cross-check for the caps. For the $2,000 and $10,000 loan examples, we compare our reading with the National Consumer Law Center’s fact sheet on state APR caps for installment loans, dated December 2025. NCLC is an advocacy organization, and its figures include fees. Its $2,000 figures are current as of September 2025 and its $10,000 figures as of August 2023. Where a statute we read says something different, the statute governs, and the page explains why.
• Check dates. Each state page shows the date its rules were last checked against these sources.
• Changes. When a state changes a rule we cover, we update the page and add a dated entry to Rule changes.

Other figures

Market figures, such as the Federal Reserve’s average rate on 24-month personal loans, are named with their release and date wherever they appear. They describe averages across banks, not what any one lender will offer you. The editorial policy explains how we choose and recheck sources.