Loan Calculator
The loan calculator computes the monthly payment for a fixed-rate loan using M = P*[r(1+r)^n]/[(1+r)^n - 1]. Enter the loan amount (principal), annual interest rate (APR), and term in months or years. The calculator shows monthly payment, total payment, and total interest. Use the loan amortization calculator to see a month-by-month breakdown.
Formula
M = P * [r(1+r)^n] / [(1+r)^n - 1]
where r = annual rate / 12, n = months
Loan calculator: frequently asked questions
What is the monthly payment formula?
M = P * [r(1+r)^n] / [(1+r)^n - 1], where P is principal, r is monthly rate (annual rate / 12), and n is number of months.
What is APR?
APR (Annual Percentage Rate) is the annual interest rate charged on a loan. The monthly rate used in calculations is APR / 12.
How much will I pay in total?
Total paid = monthly payment * number of months. Total interest = total paid - principal.
Can I change the term?
Yes. A longer term lowers the monthly payment but increases total interest. A shorter term raises the monthly payment but decreases total interest.
What is amortization?
Amortization is the process of paying off a loan with regular payments. Each payment covers both interest and principal.
Official sources
- Wikipedia: Amortization Schedule.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.