Loan Calculator
Calculate monthly payments, interest & total cost
Loan Calculator tool
Results
Monthly Payment
$0.00
Total Interest
$0.00
Total Cost
$0.00
Loan Calculator: key facts
- What it does
- Calculate monthly payments, interest & total cost
- Category
- Financial Calculators
- Cost
- Free, with no account, sign-up, or install.
- Your data
- Runs entirely in your browser — the files and text you enter are never uploaded to a server.
- Last reviewed
- . Report an incorrect result.
Understanding the Loan Calculator
Whether it is a mortgage, a car loan, or a personal loan, the questions are the same: what is the monthly payment, and how much will it cost in total? This Loan Calculator answers both, then lays out a complete amortization schedule so you can see every payment split between interest and principal.
Home buyers use it to test what they can afford at different rates; car shoppers compare financing terms; borrowers of any kind use it to understand the true cost beyond the sticker. The amortization table is the centerpiece — it reveals how early payments are mostly interest and how the balance accelerates downward over time, which a single monthly figure can never show.
Getting a result
- Choose a loan type (mortgage, auto, personal, or other) to label your calculation.
- Enter the loan amount and the annual interest rate.
- Enter the loan term and choose whether it is in years or months.
- Read the monthly payment, total interest, and total cost.
- Expand the amortization schedule to see each payment's principal, interest, and remaining balance.
Deriving the monthly payment
This calculator solves the standard amortisation equation for a level payment: the single monthly amount that clears both interest and capital by the final month of the term. It converts your annual percentage rate to a monthly figure by dividing by twelve, turns the term into a payment count, then applies the formula below.
Because interest each month is assessed on whatever principal remains, the split inside that level payment shifts continuously. The schedule the tool generates recomputes it month by month rather than estimating — interest is the outstanding balance times the monthly rate, the remainder reduces the balance, and the process repeats until the balance reaches zero.
A zero-rate entry is short-circuited rather than pushed through the formula, which would otherwise divide by zero. In that case the payment is simply the amount borrowed spread evenly across the term.
- Borrowing $10,000 over 5 years at 5.5% — the figures the page starts with — produces a payment of $191.01 a month.
- Sixty of those payments come to $11,460.70, so the loan costs $1,460.70 in interest on top of the amount borrowed.
- The first payment contains about $45.83 of interest; the final one contains under a dollar. Nothing about the payment changes, only what it is doing.
What the schedule is showing you
The shape every amortization schedule traces is the same, and the CFPB describes it plainly: a borrower "pays a fixed monthly payment, but a greater percentage is applied to the interest early in the life of the loan while a greater percentage is applied to the principal toward the end." The payment never moves; the split inside it does, every month.
That is why the balance falls slowly at the start and then gathers speed — and why term length is the lever with two opposed edges. Stretching a loan lowers the monthly figure and raises the total interest, because a smaller slice of each payment reaches the principal for longer. Run the same amount at two terms and the trade shows up in the totals rather than staying an argument.
| What you change | Monthly payment | Total interest | Why |
|---|---|---|---|
| Longer term | Falls | Rises | Principal is repaid more slowly, so interest accrues for longer |
| Higher rate | Rises | Rises | A larger share of every early payment is interest |
| Larger deposit | Falls | Falls | Less principal is financed at all |
| Extra payments | Unchanged | Falls | Anything above the scheduled payment reduces principal directly |
Reasons to use it here
- It generates a full amortization schedule, showing how each payment divides between interest and principal across the entire term.
- It accepts the term in either years or months, so it fits everything from a 30-year mortgage to a short personal loan.
- It handles a zero-interest loan correctly rather than breaking on the math, and validates inputs against impossible values.
- Everything is computed in your browser with no account, keeping loan figures private.
Where the estimate stops being reliable
An APR from an advertisement is often not the rate you are offered, because pricing depends on credit history, term, and the size of any deposit. Run the figure you have actually been quoted rather than the headline one, or the payment will look better than it will be.
Origination fees, title and registration costs, and mandatory insurance sit outside this calculation entirely. So does anything variable: a rate that can be reset, a payment holiday, or a balloon amount due at the end will all break the level-payment assumption this formula rests on.
Extra payments are not modelled here, but they are worth understanding — anything paid above the scheduled amount comes off the principal directly, which reduces every interest charge that follows and shortens the term.
Frequently Asked Questions
How is a monthly loan payment calculated?
It uses the standard amortization formula, which spreads principal and interest evenly so every payment is the same. The payment depends on the loan amount, the monthly interest rate, and the number of payments — all of which this calculator takes as input.
Why is so much of my early payment interest?
Interest is charged on the outstanding balance, which is highest at the start. Early payments therefore go largely to interest, with more shifting to principal as the balance falls. The amortization schedule shows this crossover month by month.
Does choosing a loan type change the result?
The loan-type selector is a label to help you organize your calculations; the math is the same standard amortization regardless of type. Rates and terms differ between loan types in the real world, so enter the actual rate and term for your specific loan.
Sources
- Consumer Financial Protection Bureau — What is amortization? — how a fixed payment shifts from interest toward principal, and the term-versus-interest trade
- Consumer Financial Protection Bureau — Interest rate versus APR — why an advertised APR bundles points and fees and usually exceeds the interest rate
