Air Receiver Tank Sizing Calculator #

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.

Uses the standard receiver sizing formula: V = T × (C - Q) × 14.7 / (P_high - P_low), where V = tank volume (ft³), T = time (min), C = compressor CFM, Q = demand CFM, P = pressure (PSIA). General guideline: 1 gallon/CFM for basic systems, 2-4 gallons/CFM for VSD or high-peak systems. Assumption: isothermal expansion, no moisture effects. Disclaimer: planning estimate, verify with manufacturer. How to use: enter parameters, click Calculate. Example: a 50 CFM compressor with 15 PSI differential (95-110 PSI) requiring 30 seconds reserve needs approximately 80-120 gallon tank. 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?

Use the formula: V = T x (C - Q) x 14.7 / (P_high - P_low), where V = tank volume (cubic feet), T = time (minutes), C = compressor CFM, Q = demand CFM, P = pressure (PSIA). Convert cubic feet to gallons by multiplying by 7.48. General guideline: 1 gallon per CFM for basic systems, 2-4 gallons per CFM for VSD or high-peak systems.

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

A 50 CFM compressor typically needs a 60-200 gallon receiver tank. Basic systems: 50-80 gallons. Systems with high transient demand or VSD compressors: 100-200 gallons. The tank should provide at least 10-30 seconds of reserve capacity between compressor cycles. Larger tanks reduce short-cycling, extend compressor life, and improve energy efficiency.

Does a larger air receiver save energy?

Yes, in most cases. A larger receiver tank reduces compressor cycling frequency. Load/unload compressors waste 25-35% energy at part load due to blowdown and idle power. Larger tanks allow longer run cycles and fewer blowdown events, saving 5-15% energy. For VSD compressors, larger tanks help maintain stable pressure and keep the VSD in its efficient operating range. However, excessively large tanks have diminishing returns and higher cost.