**How do you calculate the percentage change between two periods?**

**Subtraction between two consecutive periods**Just subtract Month N minus Month N-1 (the newest minus the oldest)

**Divide the result by the oldest value**Many people make mistakes in this area. You must divide by the oldest value, not the newest value.

## When is it helpful to calculate the percentage of change with Excel?

Percentage change represents the relative change between two values, expressed as a percentage. It helps understand the degree of change over time or between different entities.

You have the following document with the total sales per month. **How do we calculate the changes from one month to the next?**

## Percentage Calculation method

### 1. Subtraction between 2 months

The first thing to do is to see the difference between 2 consecutive months. The formula is straightforward

=B3-B2

And, of course, you copy this formula for the other cells.

### 2. Divide the substation by the next month's value

To calculate the percentage of increase, we will

- Use the result of the subtraction
- Divide it by the sales amount of the previous month.

=C3/B2

## Apply the percentage format

Now, you must change the format number to percentage from the **Home **ribbon.

Copy the percentage formula for the rest of your document

Between February and March, the increase is up to 38.7% (great result 😃😍)

## Related Articles

## Write the formula in a single-cell

In mathematics, it's essential to respect the order of operations. Addition and subtraction do not have the same priority as multiplication and division. This is why, to perform the subtraction before the division, we must write the subtraction in parentheses.

=(B3-B2)/B2

## Conditional formatting with icon

To highlight the increase and decrease, inserting icons with conditional formatting is a good idea.