-40.04% is the change from 512 to 307
Calculation steps:
[( 307 - 512 ) ÷ 512] x 100 = -40.04%
Formula
Percentage change = [(307 - 512) / 512] x 100
Subtract the new number by the original number
307 - 512 = -205
-205 ÷ 512 = -0.400390625
-0.400390625 x 100 = -40.04%