60% is the change from 215 to 344
Calculation steps:
[( 344 - 215 ) ÷ 215] x 100 = 60%
Formula
Percentage change = [(344 - 215) / 215] x 100
Subtract the new number by the original number
344 - 215 = 129
129 ÷ 215 = 0.6
0.6 x 100 = 60%
Example