Flow Rate Converter (Volume)

Convert among the most used volume flow units. The calculator is bi-directional and precise, built on exact SI definitions.

Common equivalents

L/s

US gpm

m³/h

Quick US gpm → L/s table

US gpm L/s m³/h

Formulas & unit definitions

Base: this tool uses m³/s internally.

  • 1 L = 1×10−3
  • 1 US gal = 3.785411784 L
  • 1 Imp gal = 4.54609 L
  • 1 ft³ = 0.028316846592 m³
  • 1 in³ = 1.6387064×10−5

Examples

US gpm → L/s: L/s = gpm × 3.785411784 ÷ 60 = gpm × 0.0630901964

m³/h → L/min: L/min = (m³/h × 1000) ÷ 60 = m³/h × 16.6667

FAQ

US vs Imperial gallons?

They are different by ~20%. Choose the correct gallon family (US or Imperial) in the dropdowns.

When to use L/s vs m³/h?

L/s is frequent in lab/process calculations; m³/h is common in HVAC, water, and industrial specifications.