Total Percent Change Calculator

You can use this quick and simple percentage change calculator to determine the total percent change for a maximum of ten distinct percent increases and decreases.

How to Calculate Total Percent Change

In a situation in which you have a sequence of percentage changes – be it reductions, increases, or a combination of both – the final percentage change represents a function of each specific increase and decrease. It is possible to determine the total percent change via a multiplicative, as opposed to additive, process. People commonly make the same error of adding and subtracting the increase and decrease in percent to determine the total change. However, adopting an additive approach leads to an incorrect solution.

For instance, let's say we are selling an item at an original price of $100. If we initially increase the cost of the item by 10% and then reduce it by 20% before increasing it again by a further 10%, we can not simply add and subtract each percentage to determine the final price. Instead, we should express the 10% increase as a factor of 1.1, the subsequent 20% increase as a factor of 0.8, and the final 10% increase as a factor of 1.1. As such, we determine the final price of the item via a process of multiplication:

$100(1.1)(0.8)(1.1) = $96.80,

According to this calculation, the final price of the item was 3.2% lower than the initial price (i.e., $100 − $96.80 = $3.20, and $3.20 / $100 = .032, or 3.2%).

Had we applied an additive approach, we would have stated that the price of the item had not changed at all (+ 10% − 20% + 10% = 0). This would have been incorrect.

This example shows us that we should always employ a multiplicative approach to computing total percent change as opposed to an additive approach.