Convert US gallons per minute to Cubic inches per second

Convert US gallons per minute (gpm) to Cubic inches per second (in³/s) instantly and accurately.

US gallons per minute (gpm)
Cubic inches per second (in³/s)

Conversion Formula

in³/s = gpm × 3.85

About US gallons per minute

The US gallon per minute (gpm) equals 3.785411784×10⁻³/60 ≈ 6.309×10⁻⁵ m³/s, the dominant volumetric flow unit in US plumbing, HVAC, and water-treatment industries. EPA showerhead standards are set at 2.5 gpm; residential water meters size at 3/4"-1" for 5-20 gpm; municipal water-distribution design uses hundreds to thousands of gpm. 1 gpm ≈ 6.309×10⁻⁵ m³/s = 3.785 L/min.

About Cubic inches per second

The cubic inch per second (in³/s) equals 1.6387064×10⁻⁵ m³/s, used in US automotive engineering for engine displacement sweep rate, fuel-injector calibration, and hydraulic actuator speed specifications. An engine injector delivering 15 in³/s of fuel corresponds to roughly 15.5 mL/s; hydraulic jacks in US equipment are rated in in³/s at operating pressure. 1 in³/s ≈ 1.639×10⁻⁵ m³/s = 0.016387 L/s.

Quick Reference Table

US gallons per minute (gpm)Cubic inches per second (in³/s)
1 gpm3.85 in³/s
2 gpm7.7 in³/s
5 gpm19.25 in³/s
10 gpm38.5 in³/s
25 gpm96.25 in³/s
50 gpm192.5 in³/s
100 gpm385 in³/s

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