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Loan calculator
Enter any amount, annual rate and term — the payment, total interest and amortization update instantly. The math is standard fixed-rate amortization, exact to the cent.
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Monthly payment
Principal—
Total interest—
Total paid—
Schedule—
How the math works
For a fixed-rate loan the monthly payment is
PMT = P × r / (1 − (1+r)−n)
where P is the principal, r the monthly rate (APR ÷ 12) and n the number of months. Each payment first covers the month's interest; the remainder reduces the balance, so early payments are interest-heavy while later ones pay down principal faster.
Frequently asked questions
Is this the same math my bank uses?
Yes — this is the standard amortized-payment formula used for fixed-rate mortgages and installment loans. Your actual bill may add property tax, insurance or fees on top of the principal-and-interest payment shown here.
Does a longer term always cost more?
A longer term lowers the monthly payment but increases total interest, because you borrow for more months. Compare 15 vs 30 years on a mortgage calculator to see the trade-off in numbers.
What is amortization?
Amortization is the schedule splitting every payment into interest and principal. The first-year table on each calculator page shows exactly how the split evolves.
How much can I afford?
A common guideline is the 28% rule: keep the payment below 28% of gross monthly income. Each result page shows the income that this implies for the specific numbers.