Data type changes in Power BI - Step-by-Step Guide

Introduction

Changing data types in Power BI helps make sure your data is understood correctly. This fixes problems like numbers being treated as text or dates not recognized properly. It ensures your reports and calculations work as expected.

When a column with numbers is imported as text and you want to perform calculations.

When date values are not recognized and you need to analyze data over time.

When you want to convert a decimal number to a whole number for counting.

When you need to change a text column to a category for filtering.

When you want to fix errors caused by wrong data types in visuals.

Steps

Step 1: Click

- Data view in Power BI Desktop

The table data is shown with columns and rows

💡 Use Data view to see actual data values and types

Step 2: Select

- Column header of the column you want to change

The column is highlighted and its properties appear in the ribbon

Step 3: Click

- Modeling tab on the ribbon

Modeling options appear including Data Type dropdown

Step 4: Click

- Data Type dropdown in the Modeling tab

A list of data types appears

💡 Common types include Text, Whole Number, Decimal Number, Date/Time

Step 5: Select

- The desired data type from the dropdown

The column data type changes and data is reformatted accordingly

Step 6: Check

- Data view and visuals

Data behaves correctly with the new type in calculations and filters

Before vs After

Before

Column 'Sales' is treated as Text showing values like '1000', '2000', '3000' but cannot be summed

After

Column 'Sales' is changed to Whole Number and can be summed in visuals and calculations

Settings Reference

Data Type

📍 Modeling tab > Data Type dropdown

Defines how Power BI interprets and processes the column data

Default: Based on data import

Common Mistakes

Changing data type without checking data format

Data may not convert properly causing errors or blank values

Preview data first and ensure values match the target type format before changing

Changing data type in report view instead of data or model view

Data type options are not available in report view

Always change data types in Data view or Model view

Summary

Changing data types ensures data is interpreted correctly for analysis.

Use the Modeling tab in Data view to change column data types.

Always check data format before changing to avoid errors.