Interest Rate Calculator Initial amount$Initial amount Payment amount$Payment amount Number of yearsNumber of years CalculateReset Interest rateInterest rate Formula i ≈ [ ( 1 + ( P/A ) ) ^{1/q}– 1 ]^{ q }– 1 q = log[ 1 + (1/N) ] / log2; N = n * 12; P = Payment Amount; A = Initial Amount; N = Number of Payments