-22.22% is the change from 540 to 420
Calculation steps:
[( 420 - 540 ) ÷ 540] x 100 = -22.22%
Formula
Percentage change = [(420 - 540) / 540] x 100
Subtract the new number by the original number
420 - 540 = -120
-120 ÷ 540 = -0.2222222222222222
-0.2222222222222222 x 100 = -22.22%