If the new number is greater than the old number then that ratio is the percent of increase which will be a positive. Y is the final amount remaining after the decay over a period of time. A is the original amount.
V 2 V 1 V 1 100.
Y is the final amount remaining after the decay over a period of time. Step 1 Get the percentage of the original number. Selling Price Cost Price 1-Gross Profit The Excel formula that would be used for this example is. Formula How to Calculate Percentage Change The percentage change between two numbers is found by dividing their difference by the number that is being changed from then multiplying that result by 100.