Let me show you how to Create a Card in Power BI with an example. A card is useful to display a single number (or metric value). For example, If we want to track the total orders, total sales value, or total quotations we sent, then we can use this Card visualization.
For this Power BI Card demo, we are going to use the SQL Data Source that we created in our previous article. So, Please refer to Connect to SQL Server article to understand the Power BI Data Source.
How to Create a Card in Power BI
Drag and Drop the Sales Amount from the Fields section to Canvas automatically create a Column Chart, as shown in the below screenshot.

Click on the Card under the Visualization section. It automatically converts the Column Chart into a Card. From the screenshot below, you can see the Card that shows the Total Sales Amount.

Create a Card in Power BI Approach 2
In order to create one, first, click on the Card present in the Visualization section. It will create a Card with dummy data, as shown in the screenshot below.

Let me drag the English Country Region Name (Dimension data) into the Fields section. As you can see, the card on the desktop shows the First Country Name as the Card value.

You can change the First function to any other Power BI supporting function.

Next, let me remove the Country Name and add the Sales Amount to the Fields section.

By default, it uses the default aggregated function called SUM. But, you can change this aggregate function as per your company’s requirement.

Let me do some quick formatting to this Power BI Card.
NOTE: I suggest you refer to the Format Card article to understand the available formatting options.

Common FAQs On Cards
A card displays the aggregated information of a single numeric measure value. However, you can change the aggregate function from default sum to Avg, min, etc. A card is the best way to represent the overall numerical information of any measure. For instance, total sales, profit, orders, etc.
The format of your visual tab has a Callout value to change the Numeric Values and a category Label option to change the label color, font, etc. In the general section, you can add the background color, title, tooltip, etc.
It default accepts one measure value or dimension (text field). However, you can create a new column combining the multiple values using concatenation and add that one as a card. The second option would be adding multiple cards side by side.
A card allows or accepts a single value, whereas a multi-row card accepts multiple values.
It was designed on top of the original card. It provides additional features such as conditional formatting, alignment, background image support, etc.