Compressors: Choosing the Right Size for Your Machine


Selecting the correct compressor size is essential for achieving optimal results in your sandblasting projects. In this article, we will discuss the factors to consider when determining the appropriate compressor size for your Vacuum Sandblasting machine. All our compressors have compressor specification recommendations on the product pages Specifications Tab.

Understanding Sandblasting and Its Air Requirements

You need continuous flow of air to keep up with the blasting process. Cubic Feet per minute (CFM) or Litres and Litres per Minute LM are the same thing, one being Imperial and the other metric measurement.

The key factors that influence the air requirements for sandblasting include:

  1. Nozzle Size and Type: The size and type of nozzle you use have a direct impact on the amount of air needed. Smaller nozzles require less air, while larger one’s demand more. A 3mm Nozzle needs less air per minute than a 6mm Nozzle. See the formula and Chart below.
  2. Pressure: The pressure at which you operate your sandblaster (PSI or Bar) affects the volume of air needed. Higher pressure settings require more air to maintain efficiency.
  3. Abrasive Material: Different abrasive materials have varying requirements. For instance, fine abrasives like glass beads need less air than coarse abrasives like steel grit. Focus in this article will be based on Garnit and Aluminium Oxide.
  4. Surface Area and Coating Thickness: As we are focusing on sandblast engraving stone this is somewhat irrelevant. The size of the surface you are working on and the thickness of the coating or material to be removed influence the air requirements. Larger areas or thicker coatings require more air.
  5. Duty Cycle: Consider how often and for how long you'll be using the sandblaster. Continuous or heavy use will require a larger compressor. If you are going to be operating high capacity them, you would be wise to consider a more powerful compressor rather than our minimum recommendation.

Calculating Air Requirements

To determine the compressor size needed for your sandblasting project, you can use the following formula:

CFM (Cubic Feet per Minute) = (Nozzle Size in Inches x PSI) / 2

This formula provides an estimate of the required CFM at a specific pressure level. Keep in mind that you should add about 20% to the calculated CFM value to account for factors like inefficiencies in the compressor system.

Choosing the Right Compressor Size

Once you have calculated the CFM required for your sandblasting project, you can begin looking for the appropriate compressor size. Here are some tips to help you make the right choice:

  1. Select a Compressor with a Higher CFM Rating: It's always a good idea to choose a compressor that provides more CFM than your calculations suggest. This ensures you have a buffer for fluctuations and variations in your sandblasting process.
  2. Consider the Duty Cycle: If you plan to use your sandblaster continuously or for extended periods, invest in a compressor with a higher duty cycle to prevent overheating and damage.
  3. Check the Compressor's Maximum Pressure: Ensure the compressor's maximum pressure rating is sufficient for your sandblasting needs, considering the pressure required for your nozzle and abrasive material.
  4. Quality and Reliability: Invest in a reputable compressor brand known for its durability and reliability to avoid frequent breakdowns and maintenance issues.


Selecting the right compressor size for sandblasting is crucial to achieving efficient and effective results in your projects. By considering factors such as nozzle size, pressure, abrasive material, surface area, and duty cycle, you can calculate the required CFM and choose a compressor that meets your specific needs. Remember that it's better to have a slightly larger compressor than one that struggles to provide enough air, as this ensures smoother and more productive sandblasting operations.