What Size Air Compressor Do I Need?

Thinking of getting an air compressor, are weWell, why notThey have a million and one different uses in the garage, in a workshop, or out in the wild. An air compressor can be your best friend during emergencies, so there’s absolutely no reason not to have one in the trunk or glove compartment of your vehicle.

But knowing which air compressor to get is the tricky part. There are several different ways to determine which air compressor is right for you. In this article, we’ll talk about how the air compressor’s size is the most crucial consideration and how you can find the right air compressor based on size alone.

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Why does size matter?

The “size” of an air compressor can mean several different things. First, size refers to airflow delivery (measured in PSI and CFM). Second, the size of the tank (measured in gallons) can also give you a hint of how much power the unit is packing. Thirdly, Size can also refer to the physical size of the tool, whether it’s a stationary, multi-tank tool or a portable one that fits in your car’s glove compartment.

All three of these meanings are important when looking at potential air compressors for your home or car. After all, the physical size of the tool is almost a direct indication of airflow delivery. Below, you can find more detailed explanations regarding pressure and volume, tank size, and air compressor style.

Pressure and Volume

Airflow pressure (PSI or pounds-per-square-inch) and volume (CFM or cubic feet per minute) are the two most crucial variables you need to understand before selecting an air compressor. Every pneumatic tool and air-filled object is designed with their manufacturer’s recommended PSI and/or CFM requirements.

Tank Size

The air compressor’s tank is of grave importance if you’re working on a schedule. A larger tank requires fewer refilling re-pressurizing and refilling sessions, but you should note that it’ll take longer for the tank to reach capacity. The efficiency of the refilling rate is determined by the air compressor’s motor size (measured in horsepower), so if you’re looking for something that’ll fill up quickly and reduce downtime, you may want to consider getting a 5-plus-HP air compressor.

Air Compressor Style

The two most popular types of air compressors used by handymen – both professional and hobbyist – are pancake and hotdog air compressors. There are too many differences to talk about, but the most significant of which are hotdogs are larger and more powerful than pancakes and are thus better at running pneumatic tools with higher PSI and CFM requirements.

What size Air Compressor should I get?

So why does size matterEssentially, the size of an air compressor determines whether it can meet each of your demands. For instance, a smaller, portable air compressor is ideal for light-duty tasks like filling beach balls and even airbrushes. A larger, beefier air compressor is needed if you have air-hungry pneumatic tools like impact wrenches or angle grinders.

The proper size and style of the air compressor depends on several other factors. Let’s see what other considerations you need to make before settling on an air compressor.

Types of projects

Need an air compressor heavy-duty mechanic workOr something for occasional home maintenanceOr perhaps you need one just to power an airbrush for painting figurinesWhatever the case, the type of projects you plan on undertaking should be the first question you ask before scouring the interwebs for Mr. Right Air Compressor.

Types of tools

Pneumatic tools (air-powered tools) have different PSI and CFM ratings. For instance, the average die grinder will need at least 5 CFM with an operating PSI of around 90, whereas a brad nailer needs only about 0.5 CFM at 70 PSI. Of course, the type of air tools you own or rent will depend on what sort of project you’re doing.

Power source

Air compressors can be powered by either electricity or gasoline. Electric air compressors are by far the more efficient and longer lasting type, but they’re not exactly portable. Unless, of course, you’re counting super-small, portable air compressors that plug into the cigarette port in your car.

Gas-powered air compressors are typically more powerful in terms of CFM and PSI delivery. The most demanding pneumatic tools like disc sanders and impact wrenches will most likely require the use of a gas air compressor that delivers more than 10 CFM at 90 PSI.


The amount of floor space the unit takes is another important consideration since a larger footprint typically translates into more power. If you plan on using your air compressor in your garage or home workshop, it’ll most likely be left in the corner of the room so the physical size of the unit shouldn’t be too big of a problem. However, in this case, you may need to rely on long pressure hoses to deliver compressed air to all corners of the shop or job site which, of course, reduces the overall pressure.

Working at various job sites with pneumatic tools will pose an entirely different problem. You may need a super-powerful gas-guzzling air compressor to deliver proper pressure and air volume, but transporting these units can be a pain in the neck and lower back. True, large air compressors are portable (come with handles and/or pneumatic tires), but taking it to different places is the challenge.

What size Air Compressor do I need?

With all things considered, you should now be able to decide on how much power your air pressure should deliver. It’s always safer to go a bit bigger than you’ll need. For instance, your job requires at least 5 CFM at 90 PSI, so the right air compressor should deliver at least 6 or 7 CFM at 90 PSI. The 1- to 2-PSI margin is more of a safety net, but it also offers the ability to use more powerful air tools if you need them.

Additionally, it’s a good idea to opt for a larger tank (5 gallons or more) if you’re using air-hungry pneumatic tools. Since they require more pressure, they’ll consume more air, and nobody likes spending 2 to 3 minutes of refilling the tank in exchange for 60 seconds of work. With a larger tank and a powerful motor, you’ll be able to do more work with each full tank.


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