Compressor Recovery Time Calculator

Compressor Recovery Time

12V pump-up time · Viair/Kleinn/ARB

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Compressor

Dual compressor setup (doubles CFM, doubles current draw)

Tank size2gal

Gallons, including any add-on tanks

0.510

Start pressure (cut-in)120PSI

Tank PSI right after the blast

60140

Target pressure (cut-out)150PSI

Where the pressure switch shuts off

100200

Tank fills in

38 sec

From 120 to 150 PSI on the Viair 400C. Effective output at this pressure: 0.85 CFM.

Compressor shootout — same tank, same window

Shorter bar = faster recovery. Click any row to swap in that compressor.

The math

Pump-up formula: t = V×ΔP / (7.48×14.7×CFM_eff)
Average pressure during fill: 135 PSI
Free-air CFM (rated): 2.62 CFM
Effective CFM at this pressure: 0.85 CFM

Compressor output falls as back-pressure rises. We apply a linear derating (CFM_eff = CFM_free × (1 − 0.75 × P_avg/P_max), floored at 15% of rated) that matches Viair's published fill times. Real-world times also depend on hose diameter, check-valve losses, ambient temperature, and battery voltage — assume ±15% on the answer.