Finance Calculators
Work out what borrowing actually costs. Every calculator here shows the full schedule, not just the headline payment, and you can download the results as a spreadsheet or PDF.
What these calculators cover
Borrowing is where small differences turn into real money. A quarter point on a $350,000 mortgage over 30 years is about $20,800 in extra interest. Stretching a $30,000 car loan from 60 months to 72 drops the payment by roughly $83 and adds about $1,200 in interest. None of that shows up in the one number a lender leads with, so every calculator here opens the whole schedule instead: what you pay each month, how much of it is interest, and what the balance is when you are done.
All three run on the same amortization engine, so a payment worked out on one page matches a payment worked out on another. Extra payments, weekly or biweekly schedules and the payoff date behave identically whichever one you open, and the schedule you download is the one on screen.
Which one you need
- Mortgage Calculator
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You are buying a house and want the real monthly cost rather than principal and interest on their own.
Property tax, homeowners insurance, HOA dues and PMI, which stops once the balance reaches 80% of the price. Extra payments show you the new payoff date.
- Loan Calculator
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Any fixed-rate loan, or you know the payment you can manage and want to work backwards to the amount it carries.
Payment and affordability modes, monthly, biweekly or weekly schedules, and extra payments with the interest they save.
- Auto Loan Calculator
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You are pricing a car and the figures from the dealer involve sales tax, fees, a trade-in or a rebate.
Sales tax charged before or after the trade-in, whichever your state does, plus documentation fees, what you still owe on the trade-in, and manufacturer rebates.
Where the numbers come from
- The annuity payment formula
- The same formula a lender uses and the same one behind a spreadsheet PMT function. Every schedule is built from it with decimal.js, so the rows add up to their own totals to the cent.
- Homeowners Protection Act, 12 U.S.C. 4901
- Sets out when private mortgage insurance can come off. The mortgage calculator drops PMI at 80% loan-to-value and shows you the month it happens.
Using these calculators well
- Compare the total of all payments, not only the monthly figure. A lower payment over a longer term usually costs more.
- A lender quotes an APR, which folds fees into the rate. These calculators work on the interest rate, so expect a small difference.
- Results assume a fixed rate and payments made on time. A variable rate or a missed payment changes the schedule.
- Nothing you type is sent anywhere. Every calculation runs in your browser.