Pulleys & Rope Efficiency Calculator

 This mechanical engineering calculator is used to calculate the efficiency of the first, second , third or more pulley system with rope or cable.


Block and tackle Efficiency approximation Formula:

A block and tackle is a system of two or more pulleys with a rope or cable threaded between them.Block and tackle - efficiency approximation(with friction factor) is calculated by using below formula

η = KN - 1(Ks × N) (K - 1)


η - mechanical efficiency of the system

K -Sheave friction factor

N- ideal mechanical advantage of the system

s - number of sheaves