If you have a spray gun or you’re looking to purchase one for a painting project at home or in the workshop, you may now be wondering what size air compressor you need to run your spray gun.

This page will serve as a guide into what size air compressor you need for your spray painting by presenting all the key considerations and relevant information!

Table of Contents

Key Considerations – Choosing an Air Compressor for Spray Painting

There are a few very key considerations you must look at when finding an air compressor suitable for a spray gun. These are:

  • Use cycle – Continuous vs Intermittent Use
  • CFM requirements & CFM rating of the spray gun
  • Pressure requirements of the spray gun
  • Duty Cycle of the air compressor
  • CFM delivery capability of the air compressor
  • Air compressor tank size (compressed air storage capacity)
  • Distance you’ll be using the spray gun from the compressor (hose length)

Are You Using the Spray Gun Intermittently or Continuously?

The first thing you must consider is whether you require require continuous or intermittent use out of your compressor for your spray guns work.

If you only require intermittent use of your spray gun then a small compressor may suffice but if you require continuous use then the compressor has to have the discharge capacity that the spray guns demands.

A typical use cycle on a spray gun in a non-assembly line environment is likely to be far less than 50% of the time drawing it’s full CFM rating.

What CFM Rating Spray Gun Have You Bought or Are You Considering Buying?

Spray guns come with CFM ratings, often expressed as SCFM ratings (as it’s a standardized unit). This can also be expressed as “Air Consumption”.

Example of a Small Spray Gun

Here’s an example of a small spray gun, the Neiko 31215A spray paint gun which is rated at an average consumption of 4.5 CFM.

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  • Nozzle size: 1.7mm (1.3mm, 1.5mm and 2.0mm also available)
  • CFM: 4.5

Example of a Medium Spray Gun

This 1.4mm spray paint gun by PNTgreen is a medium offering that has a 6 CFM average air consumption according to its technical specifications.

  • Nozzle size: 1.4mm (1.8mm also available)
  • CFM: 6

Example of a Large Spray Gun

Here’s an example of a 1.8mm larger spray painting gun by Astro pneumatic tool. It’s rated at an average air consumption of between 7-12 CFM as per the product description.

  • Nozzle size: 1.8mm
  • CFM: 7-12

What Pressure Rating Spray Gun Have You Bought or Are You Considering Buying?

All air tools, air spray guns being no exception have a recommended operating pressure.

The Neiko 31215A small spray paint gun has a working pressure of 10 PSI and an operating pressure of 40 PSI.

The PNTgreen medium spray paint gun states that in requires a working pressure of between 20-70 PSI.

Finally the Astro pneumatic tool spray gun states that the operation pressure is 50-60 PSI.

Note: it is important to not exceed the maximum operating pressure or operate on a pressure too low, to ensure you get professional spray painting results.

Air Compressor Duty Cycle

The typical duty cycle of an air compressor is normally 50% as can be seen in this Craftsman 919 manual. It states that the maximum compressor pumping time per hour is 30 minutes.

If you want to know more about air compressor duty cycles, how they’re expressed and calculated, you should read my article on air compressor duty cycles.

Here’s another example of a product manual which describes the duty cycle of a compressor in these terms:

“INTERMITTENT DUTY FORMULA

Pump-up time should not ordinarily exceed thirty (30) minutes or be less than ten (10) minutes. Shutdown periods between cycles of operation should be at least equal to the pump-up time. Note: When the compressor is regulated by constant speed control, the shutdown period is the time the compressor is operating unloaded.

This basically describes a 50% Duty Cycle.

CFM Delivery Capability of the Air Compressor

CFM ratings of air compressors tend to be based on the output of the air compressor pump.

However, to understand what ability the air compressor has to deliver CFM continuously you need to multiply the CFM rating by the Duty Cycle percentage.

So an Air Compressor CFM rating of 12 CFM with a 50% Duty Cycle would have the ability to deliver:

12 CFM * 50% = 6 CFM

Example of an Air Compressor Suitable for a Small Spray Gun

Here’s an example of an air compressor which delivers 2.4 CFM – and the product manual describes what would be determined as a 50% duty cycle. Therefore the compressor would actually deliver 1.2 CFM (2.4 CFM * 50%).

This would be suitable for a small spray gun given that you only require intermittent use. But, this compressor wouldn’t be suitable for continuous use on any of the spray guns presented in this article.

The small Neiko spray painting gun requires 4.5 CFM, if the use was intermittent and only needed 25% of the time (15 minutes per hour), then the spray gun only requires 1.25 CFM (4 * 25%). Therefore, this compressor would be capable of providing that that CFM.

However, if you required to use the spray gun on a 50% duty cycle, the spray gun would require 2.25 CFM (4.5 * 50%). The air compressor running at it’s recommended 50% duty cycle would not be able to provide the amount of CFM required by the spray gun.

It would only be able to provide the 2.25 CFM requirement if you overworked the compressor by running it on a 90-100% duty cycle which is strongly not recommended!

Example of an Air Compressor Suitable for a Medium Spray Gun

Here’s an example of an air compressor which is rated 5.30 CFM – and though product manual does not describes the duty cycle, a customer Q&A response has declared that the compressor has a 70/30 (70%) duty cycle. What would be determined as 20-25 minutes rest after each hours use.

Therefore, this air compressor is actually capable of delivering 3.71 CFM (5.3 * 70%). This is slightly undersized for continuous use of the 4.5 CFM Neiko spray gun or anything greater than that.

However, if the spray gun only required being used intermittently (50% of the time) then this compressor is suitable for not only the Neiko spray gun but also the medium PNTgreen spray gun (6 CFM * 50% = 3 CFM).

If you were to obtain a spray painting gun with a CFM of below 3.71 CFM then this compressor would be capable of delivering continuous use to that tool.

Example of a Large Air Compressor Suitable for Large Spray Guns

Here’s an example of a large Air compressor, the Ingersoll-Rand 8 Gallon twin compressor capable of delivering 11.5 CFM with 100% continuous duty cycle.

This compressor is suitable for providing continuous use to the small, medium or large (if the average was below 11.5) spray gun provided. It could even power both the small Neiko and medium PNTgreen spray guns simultaneously.

If this compressor were to have a 50% duty cycle however, and therefore would provide 5.75 CFM (11.5 * 50%) it would only be able to power the small spray gun continuously.

It would consequently no longer be able to provide continuous use to the medium or large spray gun when working with a 50% duty cycle, but instead could work intermittently if the PNTgreen tool required 3 CFM (6 * 50%) and the Astro pneumatic tool required 3.5 – 5.75 CFM (7-11.5 * 50%).

Example of an Extra Large Air Compressor Suitable for Powering Multiple Spray Guns Simultaneously

Here’s an example of an industrial air compressor which delivers 38 CFM – and the product manual describes what would be determined as a 100% duty cycle.

This is a stationary compressor, that has a continuous run & automatic stop/start feature making it capable of powering small, medium and large spray gun continuously and even all of them simultaneously!

Air Compressor Tank Size (Compressed Air Storage Capacity)

Tank size will determine how much air is available to be drawn down at any time. This is also a key enabler in keeping a compressor within it’s duty cycle.

Therefore an 12 CFM compressor with a 50% Duty Cycle can be used to run an air spray gun that’s rated at 12 CFM – if used intermittently with a sufficiently large air tank.

To keep a compressor running for at least 10 minutes with a spray gun consuming 12 Cubic Feet of air per minute for 50% of the time, the storage capacity would be:

12 CFM * 10 minutes * 50% = 60 Cubic Feet of air (at atmospheric pressure (15PSI))

As atmospheric pressure is 15 PSI and the output pressure is 90 PSI and pressure and volume are inversely proportional 15 PSI / 90 PSI = 6

Therefore, you need 1/6th the volume of air at 90 PSI

60 Cubic Feet * 1/6th = 10 Cubic Feet

10 Cubic Feet = 283 Litres

This example is to give you a basic idea on the capacity needed.

Distance You’ll be Using the Spray Gun From the Compressor (Hose Length)

Long hoses will result in pressure drop, which is not desirable. I could not find any recommendations in any of the spray gun manuals, but it can generally be recommended that the hose length should not exceed being just long enough to serve the working area.

Any hose length over 25 feet will result in pressure drop that will need to be compensated for to ensure that the spray painting gun is receiving the right operating pressure.

For further information on air hoses visit our Air Compressor Hose & Tube Guide.

FAQs (Frequently Asked Questions)

What is a good size air compressor for spray painting?

A good size air compressor would be in the range of 14-18 CFM with a large enough tank (e.g. 60 gallon) to supply your spray gun.

How many CFM do I need for a paint gun?

Depending on the average air consumption of the paint gun itself, you typically will require an air compressor that can steadily output around 15 CFM and possibly more to handle the paint gun.

Reader Questions and Responses

What size air compressor do I need for spray painting?

by jan
(nc)

I got a spray gun and its rated at for 30psi inlet 10 psi at 13 cfm.

Paint spray gun - https://about-air-compressors.com
Paint spray gun

I got a spray gun and its rated at for 30psi inlet 10 psi at 13 cfm.

Will a 3hp compressor with a 30gal tank handle this

Response:

CFM for paint gun

Well Jan, since you can get about 4 CFM of compressed air at 90 PSI for each horsepower of electric motor size on the compressor, your compressor should, theoretically, give you about 12 CFM at 90 PSI.

However, if you are running your 3 HP compressor on a 120 volt supply line, then you sure are not getting that 12 CFM at 90 PSI, since, in my opinion, there isn’t enough power in a 120 volt line to power your compressor motor enough to give you that flow and pressure.

Why not have a look at some of these pages to understand in principle how to size an air compressor.

Anyway, depending on what you are doing with your spray gun (besides painting that is), I mean, if it is air brush work with intermittent use, and you have dialed your regulator down to the minimum operating pressure for the gun that gives you the spray you want, you will be able to work with your 3HP compressor. You will, depending on how much spraying you want to do at one time, likely have to stop periodically and let the compressor catch up.


Can this CP compressor run a HVLP paint sprayer?

by elda
(dawson pa)

Can i use a HVLP paint sprayer with central pneumatic 2hp 8 gal air compressor? What size air compressor to paint a car?

Central Pneumatic 2 HP 8 Gallon air compressor
Central Pneumatic 2 HP 8 Gallon air compressor

Response:

The answer is yes, of course you can, but you may not be happy with the result.

A HVLP paint sprayer uses low pressure air, and it has a minimum compressed air supply flow rate at that low pressure to operate properly, and that is the info that you have not supplied.

What is the pressure requirement of your HVLP paint sprayer, and what is the flow requirement in CFM?

Knowing this information, and also the output of your air compressor, will help you determine if you can run your HVLP paint sprayer.

Without that info, your question cannot be answered accurately.

A 2HP air compressor as shown “should” be able to deliver 3-5 CFM at 90 PSI or thereabouts, if that helps.

What flow and pressure do you need for the sprayer please?


If you have any questions regarding what size air compressor you need for a spray painter, please leave a comment below with a photo if applicable so that someone can help you!