About This Calculator

This calculator uses the standard amortizing loan formula: monthly payment = P × [r(1+r)ⁿ] / [(1+r)ⁿ – 1], where P is the principal, r is the monthly rate, and n is the number of payments.

Common loan types

Auto loan: Typically 36–72 months at 5–10% APR
Personal loan: Typically 12–60 months at 6–36% APR
Mortgage: Typically 180 or 360 months (15 or 30 years) at 5–8% APR

Reducing interest paid

Making extra principal payments early in the loan dramatically reduces total interest, since interest is calculated on the remaining balance.