Absolute change measures the exact numerical change between two numbers and equals an ending number minus a beginning number. For example, the absolute change in a city’s population may be an increase of 10,000 residents in five years. Absolute change differs from relative change, which is another way to measure a change in numerical data. Relative change measures change in relation to another number. For example, the relative change in a city’s population may grow by 3 percent of its previous population. You can calculate absolute change for situations in which you don’t need to compare a change to another number.
Determine a beginning value from which you want to calculate a change. For the following example, use 1,000 students enrolled in a school at the beginning of the year.
Determine an ending value that represents the result of a change. In the example, use 1,100 students enrolled in a school at the end of the year.
Subtract the beginning value from the ending value to calculate the absolute change. In the example, subtract 1,000 from 1,100, which equals 100. This is the absolute change, which means the student population grew by 100 students during the year.
TL;DR (Too Long; Didn't Read)
If your result in Step 3 is negative, the absolute change is a decrease. For example, if the result is -100, refer to the change as a decrease of 100 students without referring to the negative sign.