250% is the change from 90 to 315
Calculation steps:
[( 315 - 90 ) ÷ 90] x 100 = 250%
Formula
Percentage change = [(315 - 90) / 90] x 100
Subtract the new number by the original number
315 - 90 = 225
225 ÷ 90 = 2.5
2.5 x 100 = 250%
Example