Formula untuk Penghitungan Pengganda

M = ∆Y / ∆I
M = 1 / MPS
M = 1 / (1− MPC)

Buktikan M = 1 / MPS :
M = ∆Y / ∆I
I = S (Suntikan = Bocoran)
M = ∆Y / ∆S = 1 /(∆S / ∆Y) = 1 / MPS

Buktikan M = 1 / (1− MPC)
M = 1 / MPS
MPS = 1 − MPC
M = 1 / MPS = 1 / (1− MPC)