Air compressors are sized by CFM, cubic feet of air per minute, at a given pressure. Pick one that delivers more CFM than all the tools you run at once need, and the tools work at full power. Here is how to add it up.
Step 1: Find the CFM rating of each tool
The CFM requirement is on the tool’s data plate or in its manual, usually quoted at 90 psi. Typical air demand, roughly:
| Tool | Typical air demand (CFM at 90 psi) |
|---|---|
| Brad or finish nailer, stapler | 1 to 3, used in short bursts |
| Framing nailer | 2 to 4, short bursts |
| Tire inflator, blow gun | 2 to 5 |
| 1/2 in impact wrench | 4 to 6 |
| Air hammer or chipping gun | 4 to 8 |
| Paving breaker (jackhammer) | Roughly 80 to 100 each, running continuously |
| Sandblaster | Roughly 80 to 150 depending on nozzle size |
These are guides, not specs. Always read the tool’s own rating.
Step 2: Add the tools you will run together
If two workers use two breakers at the same time, add both requirements. Tools that run in bursts, like nailers, rarely all run at the same moment, so you can use a smaller figure for them. Continuous tools like breakers and sandblasters should be counted at full demand.
Step 3: Add a margin
Choose a compressor that supplies about 25% more than your total. That covers long hoses, fittings, tool wear and a compressor that does not run at its maximum all day.
Step 4: Check pressure and hose
Most tools run at 90 to 100 psi. Long or narrow hoses lose pressure, so use a larger hose for long runs. Tell us the length and we will include the right hose.
Which of our compressors fits?
- 3-gallon electric compressor: 4.2 CFM at 90 psi. For finish nailers, staplers and inflating.
- 4-gallon hand carry compressor: for light trim and small jobs.
- Kaeser 210 CFM towable diesel: 210 CFM at about 100 psi. Runs one or two breakers, a rock drill or a sandblaster, with no outlet needed.
Frequently asked questions
How many CFM do I need for a jackhammer?
A paving breaker commonly needs roughly 80 to 100 CFM. A 210 CFM compressor can usually run one or two. Check the tool plate for the exact figure.
How many CFM do I need for a nail gun?
Only a few CFM. A small 3 or 4 gallon electric compressor is enough for finish and brad nailers.
Does a bigger tank give more CFM?
No. Tank size stores air; CFM is how much air the compressor produces. A big tank with a small pump still runs out under heavy use.
Can I run a diesel compressor indoors?
No. Diesel engines make exhaust and need open, ventilated air.