🔄 Flow Rate Unit Converter
Flow Rate Unit Converter
Inputs
Conversion Results
Enter a value to convert
Calculator Description
Flow rate — volume passing per unit time — is a core parameter of piping, water treatment, and process design. This calculator converts between ten volumetric units: m³/s, m³/h, L/s, LPM, L/h, US GPM, US GPH, CFM, cfs, and bbl/day.
What this calculator finds
The input converts to the base unit (m³/s) and every other unit updates at once. Volumetric only — mass flows such as kg/s require multiplying by density separately.
Why it matters
- Different countries and industries use different flow rate units, requiring accurate conversion
- Unit consistency is essential in piping design, valve selection, and pump sizing
- Converting flow data from foreign equipment/drawings to domestic standards is frequently needed
Formula
Flow Rate Conversion Formulas
Volumetric flow rate is defined as Q = V/t, and mass flow rate is converted by multiplying by density.
- Q — Volumetric flow rate [LPM, m³/h, GPM, etc.]
- V — Fluid volume [L, m³, gal]
- t — Time [min, h, s]
- ṁ — Mass flow rate [kg/s, lb/min]
- ρ — Fluid density [kg/m³, lb/ft³]
Common conversion factors
- 1 LPM = 0.06 m³/h = 0.2642 GPM
- 1 GPM = 3.785 LPM = 0.2271 m³/h
- 1 m³/h = 16.667 LPM = 4.403 GPM
Useful Tips
Practical tips
- Do not confuse mass flow rate and volumetric flow rate — always account for density
- US GPM (gallons) and Imperial GPM (Imp gal) are different
- Values are for steady-state flow; transient flow requires separate analysis
Limitations & cautions
- Mass flow conversion requires separate density input, which changes with temperature
- Gas volume varies greatly with pressure/temperature, requiring conversion to standard conditions (Nm³/h)
- Conversions apply to incompressible fluids (liquids); gases require compressibility considerations