Air Tank Runtime Calculator

Blasts per tank · SCFM model

train-horn.com →
2gal

Standard kits: 0.8 / 1 / 2 / 3 / 5 gal

0.510
2sec

A short toot is 1 sec; long blast ~3 sec

0.55
150PSI

Typical cut-out: 150 PSI

100200
100PSI

Below ~90 PSI most horns sound weak

60140

Horn class

Your tank holds about

2blasts

of 2 sec each before the compressor has to catch up. That's 4.5 sec of continuous horn time total.

Blast-by-blast

1
2

Compressor recovery between blasts not included — run the Compressor Recovery calculator for that.

The math

Usable air (free-air equivalent)
0.91 ft³
Horn air consumption
12 SCFM
Pressure drop window
150 → 100 PSI
Air per blast
0.400 ft³

Formula: V_usable = V_tank × (P_full − P_min) / 14.7, then blasts = V_usable / (SCFM × t / 60). Assumes isothermal expansion, no compressor running during the blast, and an idle horn valve (no leaks). Real numbers run 10–20% lower because of piping loss and temperature drop.