Air Receiver Tank Sizing Calculator #

Q: How do you size an air receiver tank?

For a transient demand above compressor output, use V = T x (Q - C) x 14.7 / (P_high - P_low), where V is tank volume in cubic feet, T is time in minutes, Q is demand CFM, and C is compressor CFM. Convert cubic feet to gallons by multiplying by 7.48. This calculator also shows a separate 1 gallon per compressor CFM planning baseline.

Quickly calculate the required air receiver tank size for your compressed air system. Enter compressor capacity, pressure range, and required reserve time to get tank volume. This quick calculator uses the standard receiver sizing formula; for full compressor system design, use our air compressor sizing calculator.

System Parameters

Units

Compressor Capacity (CFM)

Cut-Out Pressure (PSIG)

Cut-In Pressure (PSIG)

Advanced calculator

Set reserve time and peak demand when they differ from compressor capacity.

Required Reserve Time (seconds)Time to handle peak demand

Peak Demand (CFM)0 = use compressor capacity

About this calculator

For advanced compressor system design with multiple compressors and demand profiling, use the full air compressor sizing calculator.

For transient demand above compressor output, this calculator uses V = T × (Q − C) × 14.7 / (P_high − P_low), where V = tank volume (ft³), T = reserve time (min), Q = peak demand CFM, and C = compressor CFM. It separately applies a 1 gallon per compressor CFM planning baseline. Assumption: isothermal expansion, no moisture effects. This is a planning estimate; verify the pressure vessel and compressor controls with their manufacturers. Example: a 50 CFM compressor serving an 80 CFM peak across a 15 PSI storage band for 30 seconds needs about 110 gallons, so the next reference-table size is 120 gallons. Browse all pneumatic calculators.

Results

Required Tank Volume

110 gallons

Standard Tank Size

120 gallons

Pressure Differential

15.0 PSI

Gallons per CFM

2.2 gal/CFM

Continue Your Calculation

After receiver volume, size compressor FAD for total demand and verify distribution pipe pressure drop.

Size compressor →

Quick Reference #

Common values and conversions for quick reference. Use these as starting points for your calculations.

Parameter	Imperial	Metric	Notes
Standard Pressure	14.7 PSIA	1.013 bar	Atmospheric at sea level
Standard Temp	60F (520R)	15.6C (288.7K)	SCFM reference
CFM to L/s	1 CFM	0.4719 L/s	Flow rate conversion
PSI to bar	1 PSI	0.06895 bar	Pressure conversion
HP to kW	1 HP	0.7457 kW	Power conversion

Formulas and Method #

Ideal Gas Law

P x V = n x R x T

All compressed air calculations are based on the ideal gas law, which relates pressure, volume, temperature, and amount of gas. For compressed air systems, this is used to convert between standard and actual conditions, calculate pressure drop, and determine flow rates.

Standard to Actual Conversion

ACFM = SCFM x (P_std / P_actual) x (T_actual / T_std)

Convert standard flow (SCFM) to actual flow (ACFM) at operating conditions. Actual flow is used for velocity and pressure drop calculations; standard flow is used for compressor ratings and energy calculations.

Assumptions and Limitations

This calculator provides planning-level estimates. Key assumptions: air behaves as an ideal gas (valid for pressures below 300 PSIG); standard conditions are 14.7 PSIA and 60F; no moisture or oil effects; steady-state flow. Actual results may vary based on equipment condition, altitude, temperature, and system configuration. Always verify with manufacturer datasheets and professional engineering judgment for critical applications.

Receiver tank sizing chart (rule of thumb) #

Compressor CFM	Basic system (gal)	VSD / peak demand (gal)	Notes
25	25–40	60–100	~1 gal/CFM baseline
50	50–80	100–200	Typical shop compressor
100	100–150	200–400	Multiple machines / peaks

Frequently Asked Questions #

How do you size an air receiver tank?

For a transient demand above compressor output, use V = T × (Q − C) × 14.7 / (P_high − P_low), where V is tank volume in cubic feet, T is time in minutes, Q is demand CFM, and C is compressor CFM. Convert cubic feet to gallons by multiplying by 7.48. This calculator also shows a separate 1 gallon per compressor CFM planning baseline.

What size air receiver do I need for a 50 CFM compressor?

A 50 CFM compressor with an 80 CFM peak, a 15 PSI storage band, and 30 seconds of reserve needs about 110 gallons by the transient formula, so the next size in this page's reference table is 120 gallons. Confirm the selected vessel with the compressor and receiver manufacturers.

Does a larger air receiver save energy?

A receiver can reduce cycling and stabilize pressure, but energy impact depends on compressor controls, pressure setpoints, demand profile, and storage location. Quantify those conditions rather than applying a universal savings percentage.