Loan and Mortgage Payment Calculator
Enter the amount, the interest rate and the term: your monthly payment, the cost of the loan and the amortization schedule appear instantly. Everything is calculated in your browser, no sign-up needed.
- Instant monthly payment
- Insurance included
- Amortization schedule
- CSV export
100% private — Everything is processed directly in your browser: your files, voice, and image are never sent to Chatzam's servers.
How to calculate a loan payment?
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Describe your loan
Enter the amount you borrow, the annual interest rate as a percentage and the term in years.
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Add insurance
Optional: enter an annual insurance rate, such as mortgage insurance (PMI) or loan protection, calculated on the original amount, to include it in the total cost.
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Review the result
Read the monthly payment, the interest and insurance costs and the total repaid, then browse the amortization schedule or export it to CSV.
The full cost of your loan at a glance
Monthly payment and total cost
Monthly payment before insurance, total interest, insurance cost and total repaid, updated with every change.
Principal vs. interest chart
See how much of everything you repay goes to principal and how much goes to interest.
Amortization schedule
A year-by-year table you can expand month by month: principal paid, interest paid and remaining balance.
CSV export
Download the amortization schedule as a CSV file to open it in Excel, Google Sheets or LibreOffice.
How is a monthly loan payment calculated?
For a fixed-rate amortizing loan, the monthly payment stays the same and follows the formula M = P × r / (1 − (1 + r)^−n), where P is the amount borrowed, r the monthly rate (the annual rate divided by 12) and n the number of payments. Borrow $300,000 at 6% over 30 years, or 360 payments, and the monthly payment before taxes and insurance is $1,798.65, with about $347,515 in total interest. Over 15 years, the payment rises to $2,531.57, but total interest drops to about $155,683. Stretching the term lowers each payment and raises the total cost: over 20 years, you'd pay $2,149.29 a month and about $215,830 in interest.
How to read an amortization schedule
Each payment is made up of interest, charged on the remaining balance, and principal. At the start of the loan the balance is high, so interest takes the biggest share: in the $300,000 at 6% over 30 years example, the first payment of $1,798.65 includes $1,500.00 of interest and only $298.65 of principal. Month after month, the interest portion shrinks and the principal portion grows, until the last payment, which is almost all principal. That's why extra payments save the most interest when they're made early. The yearly table gives you the big picture, and the monthly detail shows the remaining balance at any given date.
What this calculator doesn't include
This calculator gives an estimate for guidance only and doesn't replace a lender's official loan offer or Loan Estimate. It doesn't include origination fees, closing costs or points, nor the APR (annual percentage rate), which rolls those costs into a single figure used to compare offers. A US mortgage payment often also covers property taxes and homeowners insurance through escrow, which aren't counted here either. Insurance is calculated on the original loan amount: at 0.5% a year on $300,000, it costs $125 a month. The tool counts it for the whole term, whereas private mortgage insurance on a conventional loan can usually be removed once you have enough equity.
Frequently Asked Questions
How do I calculate a monthly mortgage payment?
Use the formula M = P × r / (1 − (1 + r)^−n), where P is the loan amount, r the annual rate divided by 12 and n the number of months. The calculator does it for you: $300,000 at 6% over 30 years comes to $1,798.65 a month, before taxes and insurance.
What is the monthly payment on a $300,000 mortgage?
At 6% over 30 years, it's $1,798.65 before taxes and insurance; at 7%, it would be $1,995.91. Over 15 years at 6%, it's $2,531.57. The result depends on the rate you get, so enter yours for an exact figure.
How is the total cost of a loan calculated?
Total interest is the sum of all payments minus the amount borrowed; the cost of insurance is added on top. The calculator shows the interest, the insurance and the total repaid separately.
Does the calculator work out the APR?
No. The APR includes origination fees, closing costs and other charges specific to each lender, which the calculator doesn't know. Use the APR shown on each offer to compare them.
Can I use it for a car loan or a personal loan?
Yes, the formula is the same for any fixed-rate amortizing loan. Enter the term in years: $25,000 at 7% over 5 years (60 months) gives a monthly payment of $495.03.