Subtract last year's revenue from this year's revenue to find the increase in the revenue. For example, if you earned $670,000 in revenue last year and $810,000 in this year, subtract $670,000 from $810,000 to get $140,000 as an increase in revenue.
Divide the increase in revenue by the revenue from the previous year to find the rate of increase. In this example, divide $140,000 by $670,000 to get 0.2090.
Multiply the rate of increase by 100 to find the percentage increase in revenue. Completing the example, multiply 0.2090 by 100 to find the increase equals 20.90 percent.