Published on : 01 December 20213 min reading time

Calculating, reading and interpreting the rate of change can be difficult if you don’t understand the right strategy. It is indeed necessary to measure the change between two values over a specific time, which can be one year, six months or even seven days. This rate is usually given as a percentage and can be negative or positive. If you want to know how to correctly calculate the rate of change of your website, reading this guide will provide you with all the information you need.

## The principle of calculating the rate of change

It is possible to measure the rate of change of 2 values between two different dates: the starting value which is called “oldest value” and the final value which is the most recent. To do this, it is necessary to calculate the absolute change, i.e. the difference between these two values. Then divide it by the starting value. Next, multiply the result by 100. Based on this calculation, the formula to follow is the following: rate of change = ([absolute change value-starting value]/starting value)* 100. Note that understanding A/B testing on Kameleoon will allow you to do this calculation easily.

## Reading the rate of change of a website

After the calculation, it might be difficult for some to interpret the result. For this to happen correctly, you need to take into account several elements: the source, the location and the two dates that indicate the date of change. At the same time, you need to specify whether it is an increase (when the result is positive) or a decrease (when the result is negative).

However, with more realistic figures, remember that a rate of change between 10 and 15% does not necessarily mean that it is negative. It still shows that there is a progression, it is when the figure becomes truly negative that you should think about applying strategic measures.

## Mistakes to avoid when calculating the rate of change

Never confuse a decline with a slowdown. For example, a rate of change that falls from 27% to 22% is not necessarily a decline, but a slowdown. Even if the result is less than 27%, the conversion rate is still positive. This means that the variable under study is still increasing, but at a slower rate than before. On the other hand, if the conversion rate drops from 10% to 5%, this means that there is a significant decline.