Air Compressor Tank Size vs CFM

When buying an air compressor, it is significantly important to know air compressor tank size vs. CFM. It is not always evident what tank-size air compressor you need. If you don’t know the difference between tank size and CFM, it is easy to make a wrong buying decision.

First, determining the needed compressed air based on the used tool is vital. But how to determine that?

We will be looking into different factors to learn the answer to how many CFM compressors I need. Continue reading.

What is a Good CFM for an Air Compressor?

An air compressor’s “good CFM” entirely depends on the tool you will be using, taking assistance from the air compressor.

The CFM rating range of most air compressors for home use is 0.5 – 5. This is an ideal range for most home projects.

You can operate a few basic and smaller pneumatic tools using an air compressor with a 5 @ 90 PSI CFM rating. These air compressors can also involve inflating sports equipment, filling up tires, etc.

But things can be complicated when you require the use of different tools. Moreover, a variety of air compressors are available in the market. In such a situation, determining the CFM rating is quite challenging. Some research on the air tools will help you know the required CFM rating. After learning the highest CFM rating of your air tools, you can decide on an air compressor model.

Air Compressor Tank Size vs. CFM – What is the Calculation

Before finalizing an air compressor model, you need to learn how to calculate air compressor tank size and CFM rating. Thus, making a decision will be much easier.

CFM x 1.25 → round-up = minimum tank size in gallons

CFM x 1.5 → round-up = recommended tank size in gallons

CFM Requirement	1.25 Multiply	1.5 Multiply	Suggested Tank Size
20	25	30	30 gallon
40	50	60	50 – 60 gallon
65	81.25	97.5	90 – 100 gallon
80	100	120	100 – 120 gallon

For example, you have an air drill that needs 5 CFM at 90 PSI. Multiply 5 by 1.5to find the air compressor CFM rating that you will require. In this case, buy an air compressor that can deliver 7.5 CFM @ 90 PSI.

Now, if you are thinking, why should I multiply the 1.5 with the maximum CFM rating? By doing so, it is ensured that you do not continue operating the compressor at maximum capacity. It also guarantees that your air compressor can deliver more CFM than your air tool needs. This will help you prolong the compressor life.

Here is a list of required CFM ratings for the most common pneumatic tools,

Air Tool	CFM
Brad nailer	.0.3 at 90 PSI
Tire inflator	2 at 120 PSI
½” drill	4 at 90 PSI
Air hammer	4 at 90 PSI
Plasma cutter	6 at 90 PSI
7” angle grinder	5-8 at 90 PSI
Orbital sander	6-9 at 90 PSI
½” impact wrench	4-5 at 90 PSI
Mini die grinder	5 at 90 PSI
Gravity feed spray gun	9-12 at 40 PSI
Disc sander	20 at 90 PSI
90 lbs. paving breaker	90 at 100 PSI
Sandblaster	10-100
Jackhammer (single)	35-90

What Factors Play a Vital Role When Sizing an Air Compressor?

3 factors are crucial when sizing an air compressor – size, power, and discharge pressure. Let’s look at a more in-depth discussion from below.

Compressor Tank Size

An air compressor tank comes in different sizes, configurations, and orientations. Undoubtedly, buying the largest available tank size would be an ideal solution. More air will let you complete your work easily without waiting for the tan to fill up. But it has a few disadvantages as well.

The first thing is the price. Bigger air compressor price is higher than small air compressors. The second factor is the portability issue. For their bigger size, transporting is more complicated.

So, always learn your air tools CFM rating requirement and buy based on the needs.

Power

Power is another important thing to consider, referred to as Horsepower.

If you connect an air compressor to a standard power outlet, it will have no maximum of 2 HP. It is because the standard AC cord’s current rate is 15 Amps which works out at roughly 1,800 watts. A good quality air compressor delivers 4 CFM @ 100 PSI / HP.

CFM Rating

The CFM rating refers to the rate at which compressed air is delivered. This value can vary depending on the atmospheric pressure, air temperature, and relative humidity.

In order to find out the right air compressor tank size based on the CFM rating, consider reading the “Air Compressor Tank Size vs. CFM – what is the calculation.”

Is it Possible to Increase CFM Rating on an Air Compressor?

After using an air compressor for many days, you may need to increase the CFM rating of your air compressor. So, you might be thinking, is it really possible?

The straightforward answer is YES. You can do it by following 2 methods.

• Buy a new air compressor and connect the two. When buying a new air compressor to increase your CFM rating, make sure to buy the new one with a high CFM rating.
• Set the pressure regulator dial to a lower setting. Gradually do it and make sure that your air compressor performs well before setting the dial to a lower position.

Final Words

Pneumatic tools are dependent on an air compressor for efficient performance. And the performance of air compressors incredibly relies on the CFM rating and tank size.

So, understanding the relation between air compressor tank size vs. CFM is crucial. Hopefully, this comprehensive guide will help you select a suitable air compressor for your projects.

Whatever air compressor tank size you choose, make sure it meets your requirements. Improper air compressor tank size can damage your tool more than good. For this reason, match the rating of the pressure of the tool to the air compressor.