Air Compressor CFM Calculator
Size a compressor for your air tool based on its typical CFM draw and how continuously you'll run it.
Compressor size needed
How this calculator works
Every air tool has a typical CFM (cubic feet per minute) draw at a given PSI -- that's the continuous air supply it needs to run at full performance. This calculator starts from the tool's typical draw and adds headroom based on how continuously you'll run it: light, intermittent use needs less margin than heavy, continuous use, since a compressor's tank can cover short bursts but not sustained draw past its actual CFM output.
Where these numbers come from
Typical CFM and PSI requirements by tool type are averaged from air tool manufacturer specifications. Your specific tool's actual rating (usually on the tool itself or its manual) is more accurate than a general average -- use that when available, especially for tools run near-continuously like sanders or grinders.
Frequently asked questions
Why does duty cycle change the CFM I need?
A compressor's tank provides a buffer for short bursts, but for continuous or heavy use, the compressor's actual CFM output (not just tank size) has to keep up with the tool's draw, so heavier duty cycles need more margin above the tool's base rating.
Is a bigger tank a substitute for more CFM?
Only for short, intermittent bursts -- a bigger tank buys you more time before the compressor has to catch up, but it can't sustain a tool's draw indefinitely if the compressor's CFM output is genuinely too low.
Does this apply to running multiple tools at once?
No -- this estimates one tool at a time. Running two air tools simultaneously roughly doubles the CFM demand, so size accordingly if that's a real use case.
Explore the whole Calcs family here.
Not happy with our calculations or how it works? Let us know.
Have a suggestion for a calculator you don't see here? Let us know.
All GarageCalcs tools
Engine
Cam Timing Calculator Compression Ratio Calculator Coolant Mix Calculator Cylinder Head Flow Horsepower Calculator Displacement Calculator Engine Rebuild Cost Calculator Header Primary Tube Calculator Horsepower and Torque Calculator Piston Speed Calculator Rocker Ratio & Valve Lift CalculatorDrivetrain
Drag Racing Gear Calculator Driveshaft Critical Speed Calculator Gear Ratio Calculator Quarter Mile Calculator Speedometer Gear CalculatorFuel & Forced Induction
Boost Horsepower Calculator Carburetor CFM Calculator Fuel Injector Calculator Fuel Pump Calculator Turbo Pressure Ratio CalculatorShop & Body
Auto Paint Calculator Body Filler & Primer Calculator Brake Pedal Ratio Calculator EV vs Hybrid vs Gas Cost Calculator Powder Coating Calculator Pressure Washer Chemical Dilution Calculator Restoration Budget Calculator Sandblaster Compressor CFM Calculator Wire Gauge Calculator Workshop Heating (BTU) CalculatorNo calculators match your search.