Will A 3 Gallon Air Compressor Run an Impact Wrench? Size & CFM Explained

Air compressors come with different sizes of the tank and different capacities. These attributes are determinants of what the air compressor can do. A 3-gallon air compressor is a very common type that you can find easily. It is quite popular and also not expensive.

When we need to run an impact wrench, will a 3-gallon air compressor do the work? That is the question we need to answer and discuss, but first, let us have some basic knowledge of compressors and sizes.

What size air compressor do i need for impact wrench

Sizes of Air Compressor

An air compressor is a component that uses pneumatic operation to convert power to the potential energy that is trapped in pressurized air. It can be powered by gasoline or diesel, or electricity, and the size of the compressor is mainly dictated by the work it can do.

Various capacities of tanks and setups will serve different purposes. This is the primary consideration to note before purchasing air compressors. This consideration is much appreciated when you need to power an impact wrench and when you have other intentions.

In general, big tools require larger compressors. With a big air compressor size, you also have the ability to work more hours. That doesn’t imply that you must buy the biggest air compressor in the market; it is a game of finding the appropriate.

Can 3 Gallon Air Compressor Run an Impact Wrench?

The answer is a NO; a 3-gallon air compressor cannot power an impact wrench. The 3-gallon air compressor is efficient enough for purposes like running nail guns. Let me discuss the reason why it won’t work with an impact wrench.

A 3-gallon air compressor does not provide the high pressure required when working with impact wrenches. The expected air pressure generated by 3-gallon air compressors is around 0.5CFM, which won’t be sufficient to run even the smallest size of impact wrenches.

There are other reasons why 3-gallon compressors can’t run an impact wrench, the level of air pressure is not the only reason. 3 gallons of air volume is too small to power an impact wrench; the air compressor would need multiple refills; that is not practical. Also, low-pressure air compressors don’t get refilled fast. Every refill will take a while.

The new question is, what is the minimum size of an air compressor that can run an impact wrench? The question doesn’t really have a direct answer because there are different types of impact wrenches. Impact wrenches vary in capacity, size, and power requirement.

From experience, a 6-gallon air compressor is a minimum capacity that can run any type of impact wrenches. Despite the fact that the impact wrench won’t be high-capacity type, a 6-gallon air compressor won’t even be excellent for the job. The 6-gallon air compressor would require multiple refills that won’t take less than 2 minutes for each refill.

For every refill, you have to wait for the refill to be done before resuming work; that is a serious downside. The ultimate challenge would be to scout for the flawless size that would fit perfectly. Let us discuss that and the options you have.

What Size of Air Compressor Do I Need for Impact Wrench?

The impact wrench length is what the appropriate air compressor size depends on. The size of the tank can be as crucial as the maximum PSI impact wrenches are engaged.

There are air compressors with tank sizes up to 80 gallons; some are even bigger. The primary function of these tanks is simple, just to hold air. Bigger gallons will get you running for longer periods.

Some operators use impact wrenches in bursts and bits of runs instead of a continuous run over the job. Even when you work like this, 10-gallon air compressors can be a great starting point. Let’s see what the options are in the following table-

Air PressureAir VolumeTool Size
120 – 150 PSI10-15 CFM1 inch
100 PSI7 CFM¾ inch
100 PSI5 CFM½ inch
90 PSI3 CFM3/8 inch
90 PSI2 CFM¼ inch
Table 1: Power Needed to Run Different Size Tools

A specification of air pressure between 5 CFM and 10 CFM is what we recommend, coupled with over 20 gallons of tank capacity. That would serve perfectly for wrench tasks in the scope of household use. With such a combination, the operation is swift and very dependable.

A range from 8 gallons to 12 gallons of tank capacity is a wise compromise if you have cost or storage space issues. Over 3 CFM of air volume should match up with the tank capacity, which will adequately power your medium size equipment.

Bigger specifications should be good for professionals that have a high-scale business enterprise. Over 50 gallons of tank volume will be very optimal for the needed volumetric inputs and air pressure.

The tank volume can even be up to 80 gallons or more, which will get your impact wrenches running without you having to wait while you refill the tank.


When you are purchasing air compressors, the ability to run impact wrenches is obviously not the only consideration to have in mind. There are various other factors to put into consideration to note. We have discussed tank sizes and their impacts; let me mention a few other things to consider.

The horsepower rating is critical; it shows how powerful the motor is. Any rating that is no less than 1.5 HP will be very dependable in various scenarios. The normal standard is 120V or 240V of voltage outlet.

The pressure of air compressors is usually graded in Pounds per Square Inch (PSI). This is the rate at which compressed air is transferred, and it should be well over 100 PSI for an average setup that serves household uses or more.

You also don’t want a lot of noise from the air compressor; less than 100 decibels of sound is decent for a working compressor. Get a trusted product that is more than capable of undertaking your minimum needs; getting something less to save cash is definitely not a wise option when buying an air compressor.

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