Power BI - How to transform a Matrix into a beautiful Heatmap

Introduction

A heatmap is a powerful visualization type that allows you to represent data density, trends, and patterns using color gradients. In this tutorial, we will explore how to create a heatmap without using custom visuals. You will learn how to turn a matrix into a stunning heatmap. Whether you are a beginner or an advanced user preparing for Microsoft Exam PL-300 (Power BI Data Analyst), mastering heatmaps will enable you to create visually compelling and insightful reports.

What is a Heatmap?

A heatmap represents numerical values using a color gradient, making it easier to identify trends, patterns, and outliers at a glance. Instead of displaying raw numbers in a table, a heatmap uses different shades or intensities of color to convey data density or magnitude. This allows for quick insights into how values are distributed across different categories.

1) Import Sample Data

The data for this tutorial comes from the following Excel file:

student.xlsx: Contains student information

If you don't know how to import data from an Excel file into Power BI, check out the following tutorial:

We have loaded the data into Power BI without executing any transformations. The data looks as follows:

2) Create a Matrix Visual

First, let's create a simple matrix that visualizes the number of students per enrollment year and per major. Switch to the report view and create a matrix visual.

A matrix is created:

3) Add data to Matrix

Add the following data to the matrix:

The matrix will now contain data and look like this:

4) Apply Conditional Formatting

Go to the formatting option of the matrix and specify the formatting for Count of id under Cell elements. Switch the option for the Background color to On.