Loan Calculator

What this calculator does

Most loan calculators answer one question: what is the payment. Real borrowing asks three, so this page works in three directions. Given a loan, it finds the payment. Given a payment, it finds the payoff date and the total interest, and it refuses, politely but firmly, if the payment does not even cover the interest. Given a payment and a term, it finds how much that payment can borrow. Around those three it handles the parts of a real loan that simple calculators leave out: a purchase price with a down payment, fees that are financed and fees paid in cash, an estimated APR that includes those fees so offers can be compared the way lenders are required to disclose them, extra payments both regular and one-off, five payment frequencies, and the full schedule, period by period, with a payoff date whenever you give it a start.

How to use it

1. Price or amount, one or the other. Fill the purchase price and down payment and the loan amount is the difference. Or skip the price and type the loan amount directly. The results show which route was used, so a borrowed figure is never a mystery.
2. Fees are split by how they are paid, because it changes the maths. Fees added to the loan are borrowed: you pay interest on them for the whole term. Fees paid in cash are not borrowed, but they are part of what borrowing cost you, so they appear in the total cost and in the APR estimate. An origination fee of 500 on a five year loan is two quite different numbers in those two places.
3. APR is estimated from the fees you enter. The interest rate prices the loan; the APR prices the loan plus its compulsory fees, spread the same way. With no fees entered, the two are the same and the page says so. With fees, the APR comes out higher, and the gap between rate and APR is a quick measure of how fee-heavy an offer is. Your lender's official disclosure remains the legal figure; this estimate exists so you can compare two offers before the paperwork.
4. Extra payments are compared against doing nothing. Whenever extras are entered, the results show the loan without them too: the payments and interest you avoided are listed as their own lines, because "interest saved" is the entire reason to pay extra and it should never have to be worked out by hand. A one-time extra asks which payment it lands on, because a lump sum in month 6 saves years more interest than the same sum in month 60.
5. Frequencies are honest. Paying every two weeks is not the same as paying monthly twice over: there are 26 two-weekly payments in a year, which quietly adds a thirteenth monthly payment's worth of principal annually. The schedule counts real periods, so that effect shows up in the payoff date rather than being promised in the text.
6. Presets set a typical term, nothing more. Choosing car, boat, RV, equipment or land fills in the term lenders commonly use for that type, which you can change freely. The arithmetic engine is identical for every type; what differs between loan types in real life is fees, rates and rules, and those are your inputs, not hidden assumptions.

How it is calculated

The payment comes from the standard amortization formula: payment = amount financed x r / (1 - (1 + r) to the power of minus n), where r is the rate per payment period (annual rate divided by payments per year) and n is the number of payments. The schedule is then built period by period: interest on the balance at the period rate, rounded to cents like a real statement; the rest of the payment reduces the balance; extra payments go entirely to principal. The final payment settles whatever balance remains, which is why it is usually a little smaller than the rest. A 0% rate is handled as amount divided by payments. The APR estimate solves for the rate at which the payments exactly repay the amount the borrower actually receives (loan amount less cash fees, ignoring fees that were financed and are therefore inside the balance), using the same formula inverted numerically.

Worked examples

The reference loan: 10,000 at 5% over 3 years, monthly. The payment is 299.71, the first payment splits into 41.67 interest and 258.04 principal, the final payment is 299.69, and the total interest is 789.54. Every figure in that sentence can be checked against the schedule this page prints for those inputs, row by row.

Fifty extra a month: the same loan with 50 added to each payment ends in 31 payments instead of 36, with total interest of 670.07: 119.47 saved. The lump sum version: a single extra 1,000 on payment 6 ends the loan in 33 payments with interest of 663.26, saving 126.28. Early money beats regular money here, which is the general rule of amortization: payments at the start are mostly interest, so principal removed early escapes the most future interest.

A car with fees: price 25,000, down payment 5,000, an origination fee of 500 added to the loan, 6% over 5 years. The amount borrowed is 20,000, the amount financed 20,500, the payment 396.32, and the estimated APR comes out at 7.03% against a 6% interest rate. That 1.03 point gap is the fee talking: on a fee-free loan at 6%, the payment on 20,000 would be lower and rate and APR would agree.

Every two weeks: the reference loan paid every two weeks (138.18 per period, 78 periods) costs 778.38 in interest against 789.54 monthly. Modest on a small short loan, but the mechanism, one extra monthly payment a year aimed at principal, grows with the size and length of the loan.

Interest-free: 12,000 at 0% over 2 years is simply 500 a month and no interest at all, which the page handles as plain division rather than letting the formula divide by zero. Genuine 0% offers exist, usually short and usually with fees, which is why the fee fields stay available at a 0% rate and the APR estimate then does the honest work.

Reading your result

Compare loans on total interest and APR, not on the payment. A longer term always cuts the payment and almost always raises the total interest, sometimes by more than the loan's second half is worth to you; the schedule makes that visible because you can watch the balance crawl in the early periods of a long loan, when payments are mostly interest. If two offers have the same rate, the one with the lower APR estimate has the lower fees. If the payoff date matters, it is the extras and the frequency that move it, never the rate alone.

Limitations

• Fixed rate, level payments. The engine assumes the rate never changes and payments are level. Variable rate loans, balloon loans with a large final payment, and graduated payment loans follow different schedules and are not modelled here.
• Affordability is a separate question. This page computes what a loan costs, not whether it fits a budget. Lenders apply their own income and expense tests, and a payment that is arithmetically fine can still be the wrong loan.
• APR here is an estimate from your inputs. Official APR calculations follow disclosure rules that decide which fees count and how they are spread. If a fee is not entered, it is not in the estimate. The lender's disclosure document is the figure with legal standing.
• Taxes, insurance and add-ons are not built in. Vehicle and property loans often bundle insurance products or taxes into the amount financed. Enter anything that is financed as part of the price or fees so the schedule reflects it, and treat anything paid separately as a cash fee.
• Mortgages, refinancing and credit cards live on their own pages, because their rules differ: property taxes and PMI for mortgages, closing costs and break-even for refinancing, revolving balances for cards. The internal links lead to those tools.

Frequently asked questions

Why is my final payment different from the others?

Because the schedule rounds interest to cents every period, like a real statement, tiny residues build up. Instead of letting the loan dribble into an extra tiny payment, the final scheduled payment settles the exact balance plus its interest, so it lands a little under or over the regular payment: 299.69 against 299.71 on the reference loan. It is the honest ending, and lenders' schedules do the same.

Is paying every two weeks really better than monthly?

Yes, but for an unglamorous reason: 26 half-payments add up to 13 full monthly payments a year instead of 12. The extra one goes entirely to principal. Nothing about the rate changes. The saving is real but scales with the loan: small on a short loan, substantial on a long one. Beware third-party services that charge a fee to do this for you; the extra payment field achieves the same thing free.

What is the difference between the interest rate and APR?

The rate prices the borrowed money alone. APR prices the borrowed money plus the compulsory fees of getting it, expressed as a rate over the same term. That is why APR is the comparison number regulators settled on: two loans at 6% are not equal if one carries 500 of fees and the other none, and APR is where that shows. This page estimates APR from the fees you enter; the worked example above shows a 6% loan pricing out at 7.03% once a financed fee is counted.

Can this calculator handle a 0% loan?

Yes. At a rate of zero the payment is the amount divided by the number of payments, and the schedule shows interest of zero throughout. Keep the fee fields honest at 0%: interest-free offers are often fee-carried, and a 0% loan with a financed fee has an APR above zero, which the estimate will show.

How much extra should I pay each month?

Try the number in the extra field and read the two saved lines: interest saved and payments saved. The pattern to notice is that the first extra dollars do the most work, because they attack principal while the balance, and therefore the interest charged on it, is at its largest. There is no universal right amount; there is a right way to compare, which is those two lines against whatever else the money would do.

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• Refinance Calculator
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Method: standard amortizing payment formula on the amount financed; period-by-period schedule with interest rounded to cents at each step; final payment settles the exact remaining balance; extras applied wholly to principal; APR estimated by solving the same formula against the amount the borrower receives after cash fees. Last reviewed: 13 October 2026.