In this article, we will learn about how the choose/identify the capacity (DTUs) of the Azure SQL that we would like to procure.

In the traditional way, below is the list of factors that we need to consider while purchasing the infrastructure for our Microsoft SQL Server.

  • CPU Capacity (number of cores)
  • RAM
  • Hard Disk
  • Licenses (Express, Standard, Enterprise)

In Azure’s Platform as a service (PAAS) way, we don’t need to worry about most of the above factors. We just need to consider DTUs (Database Transaction Units) and of course the size of the database. So, the capacity of the database is calculated in DTUs.

Here is the definition of DTUs from the official site.

The Database Transaction Unit (DTU) is the unit of measure in SQL Database that represents the relative power of databases based on a real-world measure: the database transaction.
One of my customers have asked me on how do I arrive at the required DTUs that for my Database server if I need to migrate to Azure from On-Premise.
Here is the tool named “Azure SQL Database DTU Calculator”  that is used to calculate the required DTUs.

Important point to Note: Please note that this tool provides a tentative information and it’s not official and here is the disclaimer from the tool’s website.

This site is in no way affiliated with, nor has it been authorized, sponsored, or otherwise approved by, Microsoft Corporation. All product names, logos, copyrights, and trademarks mentioned are acknowledged as the registered intellectual property of their respective owners.

Let’s discuss on how to utilize the tool.

  • In the Azure SQL Database DTU Calculator’s page, click on the “Download Command Line Utility” link,
  • The above link contains a PowerShell script which you need to execute in your on-premise Server where your current SQL Server is being hosted.
  • Capture the Performance counter’s in a .CSV file (the script will capture the details in a .CSV file).
  • Come back to Azure SQL Database DTU Calculator’s page. Provide the number of CPU cores of your current Server where SQL is being hosted in the “Cores” textbox shown in the below screen capture and upload the .CSV file and then click on the “Calculate” button.

  • That’s it. The Azure SQL Database DTU Calculator will provide you the details about what performance tier (DTUs) you should look for your Azure SQL databases.
  • I ran the power shell script in one of my test machine and below are the reports that the Azure SQL Database DTU Calculator has provided.


For my Analysis, it has suggested that I go for to P2 tier. Below are the details about the P2 tier.

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For more details, please visit the Azure SQL Database DTU Calculator page.