For example if 10 of 50 is 5 then 5 of 50 is 250 since 250 is half of 5. Reverse percentage can be calculated by dividing a known amount by 1 minus the discount rate or 1 plus the tax rate. 400 100 percent - 20 percent x original price.
Multiply the resultant number by 100.
To calculate the final price after discount we will have to multiply the actual price with the discount. How to Calculate Reverse Sales Tax. Multiply the resultant number by 100. It is easy to calculate 5 by simply dividing 10 of the original price by 2 since 5 is half of 10.