Turning numbers red when they are negative is not very difficult in Excel. Here are several techniques.

Currency format turns negative numbers red

Among number formats present in Excel, only the monetary format offers the option of putting negative values ​​in red.

From the Ribbon (Home tab), if you choose the currency format, negative numbers are displayed in the same color as positive numbers.

• Open the number customizations menu.

• In the Currency section, you can choose to display negative numbers in red.

Customize number format

For all other formats, there are two different techniques that allow you to display negative numbers in red.

When you open the menu Cell Format > Number > Category > Custom, you see that there already exist certain formats with the indication [Red]

Detail of the number format code

Creating a custom code for a number follows the following rule.

Positive number;Negative number;Zero;Text

To put a negative number in red, it is the second part of the code that will interest us.

If, for example, you want to put negative percentages in red, you will simply write:

0%;[Red]-0%

Or if you want to keep decimals:

0,00%;[Red]-0,00%

• Don't forget the sign -
• If you forget it, the negative number will appear in red but without the negative sign. ????????????

The colors offered

Here is the list of 8 colors that you can add to your custom number formats in Excel

• Noir
• White
• Red
• Vert
• Blue
• Saffron yellow
• Magenta
• Cyan

Conditional formatting

The other technique that allows you to put a negative number in red is to create a rule of conditional formatting.

Open the Conditional Formatting > New Rule menu

1. Select the rule Apply formatting only to cells that contain.
2. Then choose the option Cell value.
3. With the option Lower than.
4. Indicate the value from which the rule will apply (here 0).
5. Finally, click the button Format.

Choose the type of format you want when the rule will be detected.

With the following result in the spreadsheet, the negative numbers are red and bold

Which method to choose?

Using conditional formatting is the preferred method because it offers a much greater range of format customization (bold, italic, cell background color, etc.)

You will find additional information on create a custom number format on the Microsoft site.