How to Calculate Monthly Loan Payments
Updated 2026-06-21
To calculate a monthly loan payment, divide your annual interest rate by 12 to get a monthly rate, then apply the standard amortization formula using the loan amount and total number of monthly payments. The fastest way is to enter three numbers — loan amount, annual interest rate, and term in years — into a loan calculator and read the result.
The three inputs you need
Every fixed-rate loan or mortgage payment comes down to the same trio:
- Loan amount (principal): the balance you're borrowing, after any down payment.
- Annual interest rate (APR): the yearly rate, for example 6.5, not the monthly fraction.
- Term: how long you'll repay, usually in years (30-year mortgage, 5-year auto loan).
With those three values, the Everyday Calculators loan tool returns your fixed monthly payment instantly. Because it runs entirely in your browser, your loan figures are never uploaded to a server — useful when you're modeling a mortgage you'd rather keep private.
A worked example
Say you're borrowing $300,000 at 6.5% over 30 years:
- Monthly rate = 6.5% ÷ 12 = roughly 0.5417% per month.
- Number of payments = 30 × 12 = 360.
- Applying the amortization formula gives a payment near $1,896 per month.
Over the full 30 years you'd pay about $682,600, meaning roughly $382,600 in interest on top of the original $300,000. Seeing that interest total is exactly why a payment calculator beats guessing — it shows the true cost, not just the monthly hit.
Read the amortization schedule
A single payment number hides an important detail: early payments are mostly interest, and later payments are mostly principal. An amortization breakdown shows, for each month:
- How much of the payment goes to interest.
- How much goes to principal.
- Your remaining balance.
On that $300,000 mortgage, your first payment sends about $1,625 to interest and only $271 to principal. By the final year, that ratio flips almost completely. This is why paying a little extra early — or choosing a shorter term — saves so much: you knock down principal before interest can accumulate on it.
Common pitfalls to avoid
- Entering a monthly rate as the annual rate. Always use the yearly APR; the tool converts it for you.
- Forgetting the term unit. A "60" could mean 60 months or 60 years — confirm whether you're entering years or months.
- Treating the payment as your full housing cost. A mortgage payment from any calculator covers principal and interest only. Property tax, homeowners insurance, and PMI are added on top by your lender.
- Comparing loans by payment alone. A lower monthly payment often just means a longer term and more total interest. Compare the total-interest figure too.
Beyond loans
The same tool also handles the everyday math around a loan decision: percentage changes, splitting a tip across a group, BMI, and exact date or age differences for things like closing timelines. Everything runs offline, so you can model scenarios on a flight or a spotty connection.
Ready to see your number? Open the Everyday Calculators and enter your amount, rate, and term to get your payment and full schedule in seconds.