Flow Rate Converter

A flow rate converter translates volumetric flow — volume passing a point per unit time — between common engineering units. This free flow conversion calculator and flow rate conversion online tool handles L/s, L/min, SLPM, m³/h, m³/s, US gpm, cfm, ft³/h (SCFH-scale), and ft³/s (cusec).

Use it for plumbing, HVAC air flow, process piping, and lab gas lines. All flow unit conversion and flow rate unit conversion runs locally — nothing is uploaded.

Process datasheets often quote m³/h; lab and small-bore specs use L/min. The exact factor:

L/min = m³/h × 1,000 ÷ 60 = m³/h × 16.667  ·  m³/h = L/min × 0.06

Searches like convert cubic meter per hour to lpm, flow rate conversion m3 hr to lpm, and flow rate conversion formula for metric units use this step. Example: 6 m³/h = 100 L/min · 1 m³/h ≈ 16.67 L/min.

This page works as a live flow rate conversion table and water flow conversion calculator once you enter the numeric rate — the unit factors are the same for water and other incompressible liquids at steady state.

US plumbing and pumps use gallons per minute (gpm). Conversion to metric:

1 US gpm = 3.785 L/min = 0.0631 L/s

Water flow rate conversion and water flow unit converter searches for irrigation, pool pumps, and municipal supply often start in gpm. 10 gpm = 37.85 L/min · 60 gpm = 227 L/min (≈ 13.6 m³/h).

Convert flow units between L/s and L/min by ×60 or ÷60 — both are in the dropdown for instant scaling.

HVAC and compressed gas specs use cubic feet per minute (cfm) or standard cubic feet per hour (SCFH). At the same temperature and pressure reference, scfm and cfm use the same volume-per-time math — "standard" defines which T and P. This tool converts the numeric rate between cfm, ft³/h, and metric units.

Key relations: 1 cfm ≈ 28.3 L/min ≈ 0.472 L/s · 1 ft³/h (SCFH-scale) ≈ 0.472 L/min · 60 cfm = 3,600 ft³/h. Convert scfh to scfm calculator: divide SCFH by 60 for SCFM. Convert scfm to scfh calculator: multiply by 60.

Slpm to lpm, slpm to lpm calculator, slpm to lpm conversion online, and lpm to slpm converter: standard litres per minute (SLPM) at STP is treated as equivalent to L/min for unit scaling — select SLPM or L/min in the dropdown. Scfh to lpm converter / scfh to l min: use ft³/h → L/min (× 0.472 L/min per ft³/h).

Air flow rate converter and gas flow rate conversion / gas flow rate conversion calculator for duct and regulator sizing convert cfm ↔ L/s here. Convert acfm to dscfm needs actual vs standard temperature/pressure correction — not a single fixed factor.

Hydrology and civil engineering use cusec (cubic feet per second, ft³/s). Cusec convert to liters: 1 ft³/s ≈ 28,317 mL/s = 28.3 L/s ≈ 1,700 L/min. Select ft³/s (cusec) in the From unit.

Large pipelines may quote m³/s. 1 m³/s = 1,000 L/s = 60,000 L/min = 3,600 m³/h. Convert between m³/s, m³/h, and L/min using this tool before hydraulic calculations.

This tool converts volume flow rate units only. Mass flow (kg/h, lb/h) requires density:

mass flow = volumetric flow × density  ·  ṁ = Q × ρ

Searches like convert flow rate to mass flow rate, convert volumetric flow to mass flow, volume flow rate to mass flow rate converter, mass flow rate conversion, and convert lb hr to scfh natural gas need ρ or gas composition — use the Density Converter for ρ, then ṁ = Q × ρ. Convert mass flow rate to molar flow rate also needs molecular weight.

Flow to volume conversion / flow rate to volume conversion: volume = flow rate × time (e.g. L/min × minutes = litres delivered).

Convert flow rate to velocity in pipe, velocity to flow rate conversion, and convert velocity to flow rate use Q = A × v (flow = cross-section area × mean velocity). Pipe diameter is required — not a unit conversion.

Convert psi to flow rate, convert bar to flow rate, flow rate to psi conversion, convert mmh2o to flow rate, and convert inches of water to flow rate involve orifice, valve, or pump curves — pressure units convert on the Pressure Converter, not to flow directly.

Other out-of-scope items: flow rate converter cytiva (chromatography hardware brand), convert cc min to lb hr (mass flow), sccm gas flow conversion at differing STP definitions — convert the numeric SCCM/SLPM value between L/min and cfm here after confirming your standard conditions.

For pure volumetric flow conversion, volumetric flow rate conversion, and flow rate unit conversion calculator between L/s, L/min, gpm, cfm, m³/h, and cusec, this page is the right tool.