Are you looking to buy a new air compressor but don’t know what size you need? Don’t be fooled into believing that the tank size of the air compressor is all you need to consider. A larger tank doesn’t necessarily correlate to more power. In fact, all a larger tank does is allow for you to use the air compressor longer between cycles.
If you really want to know what air compressor to buy, you should pay more attention to PSI and CFM ratings. These two metrics will determine whether or not a given compressor can power your air tools adequately. Because all air tools have specific PSI and CFM ratings at which they were designed to operate, choosing an air compressor that’s on par with these ratings is crucial. If your air compressor doesn’t have enough PSI or CFM, then your air tools aren’t going to work properly.
Table of Contents
- How Many PSI Do I Need?
- How Many CFM Do I Need?
- Other Considerations You Should Make
- Air Tool Consumption Chart
So, what size air compressor do you need? One with high enough PSI and CFM ratings. Unfortunately, there’s no one size fits all answer to this question. In order to determine what size compressor you need, you first need to take note of the PSI and CFM requirements of your specific air tools. Once you’ve done that, then selecting a good air compressor becomes a whole lot easier.
If you’d like to learn more about PSI and CFM and how they relate to your air tools, then keep reading. We’re going to discuss these metrics in a bit more detail so you can determine what size air compressor you need.
At the end of this article there’s a chart with a list of common air tools, their respective PSI and CFM requirements, and what size air compressor is needed to power them. You can check it now by clicking the button below.
How Many PSI Do I Need?
PSI or pounds per square inch is the metric that measures force or pressure. If an air compressor is rated at 150 PSI, it simply means that it’s able to produce up to 150 pounds per square inch of pressure. It doesn’t mean that it provides this amount to your tools at all times, but only that it can if you need it to.
Most air compressors for home use are rated for 150-175 PSI, which is more than enough for most applications. Being that most air tools operate around the 70-90 PSI range, just about any modern compressor will be able to provide sufficient PSI. Just to be safe, however, you’ll want to check the specific PSI requirements of your air tools. If you have any tools that need more than 150 PSI then you’ll need to choose a compressor accordingly.
In short, however, the amount of PSI you need will be determined by the amount of PSI required to run your specific air tools. If the main air tool you’ll be using is a framing nailer that needs 90 PSI to operate, then pretty much any compressor will provide enough PSI to do the job.
How Many CFM Do I Need?
CFM stands for cubic feet per minute. While PSI measures the force or pressure of the air being supplied, CFM measures its volume. Like PSI, if a given air compressors CFM rating doesn’t match or exceed the CFM requirements of your air tools, it’s not going to work.
Unlike PSI, however, air compressor CFM ratings vary drastically. While most air compressors for home use are rated for 150-175 PSI, CFM ratings aren’t so consistent. With that being said, you’ll want to spend a bit of time looking at the CFM ratings of all your air tools and find out which one requires the most CFM. Once you’ve discovered the tool with the highest CFM requirement, you’ll want to multiply that number by 1.5 just to give yourself a buffer. The number you get will be the amount of CFM an air compressor needs to provide in order to be suitable for your needs.
For example, if your most air consuming tool is an air hammer with a CFM rating of 3.38 then you’ll want a compressor capable of producing 5.07 CFM.
*3.38 x 1.5 = 5.07
If you plan on using multiple air tools at the same time, you’ll need to add their respective CFM requirements together and multiply that number by 1.5 in order to determine how many CFM you’ll need.
Related Articles:
- The Difference Between PSI and CFM Explained
- Air Compressor Measurements Explained (PSI, CFM, HP, & more)
Other Considerations You Should Make
Aside from PSI and CFM, there are a few other considerations you should make. The first is tank size.
Tank Size
I mentioned earlier that tank size isn’t as important as PSI and CFM ratings, however, it’s not completely irrelevant.
Smaller tanks have to cycle on more frequently in order to keep the tank pressurized. If you’re using air tools that require continuous air such as grinders, paint sprayers, or sandblasters, then this could be an issue. Essentially you’ll have to stop and wait for the cycle to end before you can resume work. With that being said, if you’re using the above mentioned tools or others like them, then you may want to invest in a compressor with a larger tank to avoid any potential interruptions.
If you’re using tools that only require short bursts of air such as a nail gun or an impact wrench, then a small tank should be sufficient. Three to six gallons should be enough.
Duty Cycle
As stated in a previous article, duty cycle is the portion of time a compressor pump runs relative to the compressor’s total cycle time. The total cycle time is how long it takes to reach cut-out pressure, turn off, and reach cut-in pressure during use. This cycle time is important as it gives the compressor a chance to cool off before cycling on again.
Duty cycles are generally given as a percentage: 25%, 50%, 75%, and 100%. The percentage value equates to how long the compressor should run during a given time.
For example, if an air compressor has a duty cycle of 50%, then over the course of one hour the compressor should only run for 30 minutes. If you force the compressor to run longer by using air tools that require more air than the compressor can give, you run the risk of damaging your compressor.
So, what duty cycle do you need? Again, it depends on what you’re going to be using it for. The higher the duty cycle the longer your compressor can run without risk of damage. If you’re using air tools that require continuous air, then you should opt for a compressor with a duty cycle of 75% or 100%. For general home use you’ll be fine with 50% duty cycle.
Related Article: Air Compressor Duty Cycles Explained
Air Tool Consumption Chart
If you’re anything like me, you don’t feel like looking through the owner’s manual of all your air tools looking for CFM requirements. I get it. That’s why I put together this handy chart. In the table below you’ll see a list of common air tools, their respective PSI and CFM requirements, the amount of CFM an air compressor needs to be able to provide in order to power them, and an air compressor recommendation.
Please keep in mind that these numbers are based on air tools that are probably different from the ones you own. That being said, you should always check the CFM requirements of your air tools prior to making a purchase. No seriously, check them.
| Tool | Working Pressure | CFM Requirement | Recommendation |
|---|---|---|---|
| Brad Nailer | 1.0 CFM @ 90 PSI | 1.5 | Makita Mac210Q (2 CFM) |
| Framing Nailer | 4.2 CFM @ 90 PSI | 6.3 | Makita Mac5200 (6.5 CFM) |
| Finish Nailer | 1.0 CFM @ 90 PSI | 1.5 | Makita Mac210Q (2 CFM) |
| Palm Nailer | 1.5 CFM @ 90 PSI | 2.25 | Porter Cable C2002 (2.6 CFM) |
| Flooring Nailer | 2 CFM @ 90 PSI | 3 | Stealth 4.5 Gallon (3.0 CFM) |
| Roofing Nailer | 2.5 CFM @ 90 PSI | 3.75 | Craftsman CMXECXA0331042 (4.0 CFM) |
| Pin Nailer | 1.0 CFM @ 90 PSI | 1.5 | Makita Mac210Q (2 CFM) |
| Siding Nailer | 2.5 CFM @ 90 PSI | 3.75 | Makita Mac2400 (4.2 CFM) |
| Stapler | 1.0 CFM @ 90 PSI | 1.5 | Makita Mac210Q (2 CFM) |
| 1/4 Ratchet | 4.2 CFM @ 90 PSI | 6.3 | Makita Mac5200 (6.5 CFM) |
| 3/8 Ratchet | 4.4 CFM @ 90 PSI | 6.6 | Makita Mac5200 (6.5 CFM) |
| 1/2 Impact Wrench | 4.0 CFM @ 90 PSI | 6 | Makita Mac5200 (6.5 CFM) |
| 1/4 Angle Die Grinder | 4.0 CFM @ 90 PSI | 6 | Makita Mac5200 (6.5 CFM) |
| Air Hammer | 4.4 CFM @ 90 PSI | 6.6 | Makita Mac5200 (6.5 CFM) |
| 6″ Palm Sander | 4.5 CFM @ 90 PSI | 6.7 | Makita Mac5200 (6.5 CFM) |
| HVLP Paint Spray Gun | 8.0 CFM @ 30 PSI | 12 | Ingersoll Rand SS5L5 (18.1 CFM) |
| 3″ Cut off Tool | 4.0 CFM @ 90 PSI | 6 | Makita Mac5200 (6.5 CFM) |
| Reciprocating Saw | 3.0 CFM @ 90 PSI | 4.5 | California Air Tools 10020C (5.3 CFM) |
| Tire Inflator | 1.0 CFM @ 100 PSI | 1.5 | Dewalt DWFP55126 (2.6 CFM) |
| 3/8 Air Drill | 4.0 CFM @ 90 PSI | 6 | Makita Mac5200 (6.5 CFM) |
| Needle Scaler | 4.0 CFM @ 90 PSI | 6 | Makita Mac5200 (6.5 CFM) |
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