Let say If you want to calculate the percentage increase in sales then the formula will be

For Example if

New Sales = 100

Old Sales = 50 then

percentage increase = ?

percentage increase = (100-50)/50 *100

= (50/50) X 100

= 1(100)

= 100%

Percent change = { [ (New sales) - (Old sales) ] / (Old sales) } x (100)

For Example if

New Sales = 100

Old Sales = 50 then

percentage increase = ?

percentage increase = (100-50)/50 *100

= (50/50) X 100

= 1(100)

= 100%