-40% is the change from 540 to 324
Calculation steps:
[( 324 - 540 ) ÷ 540] x 100 = -40%
Formula
Percentage change = [(324 - 540) / 540] x 100
Subtract the new number by the original number
324 - 540 = -216
-216 ÷ 540 = -0.4
-0.4 x 100 = -40%
Example