-38.48% is the change from 512 to 315
Calculation steps:
[( 315 - 512 ) ÷ 512] x 100 = -38.48%
Formula
Percentage change = [(315 - 512) / 512] x 100
Subtract the new number by the original number
315 - 512 = -197
-197 ÷ 512 = -0.384765625
-0.384765625 x 100 = -38.48%