Building a Bullet Chart with SVG in Power BI using DAX

Meaningful KPIs

Building custom visuals in Power BI allows us to display data uniquely and meaningfully, enhancing our dashboards' clarity and insightfulness. One powerful, flexible method uses SVG (Scalable Vector Graphics) with DAX to render custom charts. In this tutorial, we’ll create a simple yet informative bullet chart using DAX and SVG that dynamically reflects key performance metrics.

Why Use SVG in Power BI?

SVG in Power BI provides a way to customize visuals beyond the standard options. With SVG, we can create shapes, colors, and layouts that adjust according to our data, making our visuals not just static but responsive to performance changes.

Bullet Chart Breakdown

Our bullet chart will feature:

1. An Actual Value Bar: This represents the current metric we’re tracking.

2. A Target Line: This indicates the goal or past performance for easy comparison.

3. A Performance Dot: A small dot that dynamically changes color based on performance thresholds, allowing viewers to assess performance quickly.

The Core SVG Code

Here’s the main SVG snippet to create our dynamic bullet chart:

VAR _ActionDot = "<circle cx=""10"" cy=""10"" r=""5"" fill=""" & _ActionDotFill & """/>"

Let’s break it down:

• cx and cy set the center coordinates of the circle (our dot) to position it within the SVG canvas.

• r specifies the radius, creating a small dot with a 5-pixel radius.

• fill sets the color based on a variable, _ActionDotFill, which uses conditional logic to select colors (e.g., red for low performance, blue for high).

Building the Chart with DAX

In the full DAX code, we set up several key variables:

• _Actual and _Target: These are the actual and target values we want to compare.

• _Max: Calculates the maximum value across our data to normalize the bar length.

• _ActualBar and _TargetLine: Define the actual bar and target line lengths based on normalized values.

• _ActionDotFill: Changes color based on performance levels, providing a quick visual assessment.

Bringing It All Together in Power BI

To display this SVG bullet chart in Power BI:

1. Add a table or matrix visual.

2. Insert the DAX measure as a column in the visual.

3. Set the column’s Data Category to Image URL to render the SVG code as an image.

Why This Chart Stands Out

This custom SVG bullet chart gives viewers a dynamic snapshot of performance. The color-coded dot, positioned with respect to the target and actual bars, instantly communicates whether performance is on track. It’s a simple, visually intuitive way to enhance your Power BI dashboards. Thank you so much to Kurt Buhler for a great article about this.

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