CFM Calculator
Answer the first sizing question: how much cfm do you need? Estimate from your air tools with duty cycle, or from motor HP, and get a recommended compressor size range.
Calculate your required CFM
Compressed Air Calculators and Sizing Tools
The same first-pass math our engineers use, with every formula and assumption in the open. No form fill, no email wall, just answers you can check.
Free compressed air calculators
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Air Receiver Tank Calculator
Size your receiver with the standard formula from cfm demand, allowable pressure drop, and hold time. Outputs gallons and the next standard tank size up.
Size your receiver tank
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Compressed Air Leak Calculator
See your annual compressed air energy bill and the 20 to 30 percent the US DOE says leaks typically take, from three inputs: HP, weekly hours, and your kWh rate.
Estimate your leak losses
The Brabazon Toolbox: 17 more calculators
The full engineering toolbox covers compressed air, pumps, and cost of ownership. Same rules: every formula shown, realistic defaults, no email wall.
Compressed air
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Compressor Sizing Calculator
Add up your air tools and duty cycle to get the CFM and HP range you need.
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Leak Cost Calculator
Price out compressed air leaks by orifice size, in dollars per year and wasted HP.
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Energy Cost Calculator
Annual, monthly, and 10 year electricity cost from HP, load, and hours.
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Pressure Reduction Savings
Every 2 PSI of discharge pressure is about 1 percent of compressor energy.
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VSD Savings Calculator
Estimate what a variable speed drive saves at your load profile.
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Air Receiver Sizing Calculator
Size a receiver from demand, hold time, and allowable pressure drop.
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Pipe Sizing Calculator
Check pressure drop in your air main with a clear pass or fail verdict.
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SCFM to ACFM Converter
Convert between standard and actual CFM for your altitude and conditions.
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Nitrogen Generation Savings
Compare delivered nitrogen against generating it on site.
Pumps
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Pump Sizing Calculator
Total dynamic head, brake HP, and a motor size from your flow and system.
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Pump Energy Cost Calculator
Annual pumping cost and what a 10 point efficiency gain is worth.
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NPSH Available Calculator
Check suction conditions against NPSH required before the pump cavitates.
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Pump Affinity Laws Calculator
What a speed change or impeller trim does to flow, head, and horsepower.
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Pipe Flow Velocity Calculator
Check line velocity against suction and discharge guidelines.
Cost of ownership
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Downtime Cost Calculator
Put a dollar figure on every hour of unplanned downtime.
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Utility Rebate Estimator
Planning level rebate estimate for efficiency projects in WI, IL, MN, and MO.
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Rent or Buy? Rental vs Purchase Calculator
Compare rental against ownership month by month and find break-even.
When the estimate matters, measure
Every tool here is planning-level math. A compressed air audit replaces the rules of thumb with a week of logged data from your own system. Related reading: SCFM vs CFM explained and the air compressor sizing guide. Or call 800.825.3222 any time. We answer 24/7.