215.79% is the change from 266 to 840
Calculation steps:
[( 840 - 266 ) ÷ 266] x 100 = 215.79%
Formula
Percentage change = [(840 - 266) / 266] x 100
Subtract the new number by the original number
840 - 266 = 574
574 ÷ 266 = 2.1578947368421053
2.1578947368421053 x 100 = 215.79%