870% is the change from 30 to 291
Calculation steps:
[( 291 - 30 ) ÷ 30] x 100 = 870%
Formula
Percentage change = [(291 - 30) / 30] x 100
Subtract the new number by the original number
291 - 30 = 261
261 ÷ 30 = 8.7
8.7 x 100 = 870%
Example