Flow Rate Converter
Convert between different flow rate units including liters per second, gallons per minute, cubic meters per hour, and more
Conversion Settings
No value entered
Conversion Result
Conversion result will appear here
Enter a value and click "Convert" to start
Common Flow Rate Applications:
HVAC Systems:
- • Air handling units: 1,000-50,000 CFM
- • Residential furnaces: 800-2,000 CFM
- • Chilled water: 2-5 GPM per ton
Water Systems:
- • Garden hose: 5-10 GPM
- • Fire hydrant: 500-1,500 GPM
- • Kitchen faucet: 1.5-2.5 GPM
About Flow Rate Converter
A comprehensive flow rate converter tool that allows you to convert between various volumetric flow rate measurement units. Whether you're working in fluid mechanics, hydraulic engineering, HVAC systems, or process engineering, this tool provides accurate conversions between liters per second, gallons per minute, cubic meters per hour, cubic feet per minute, and many other flow rate units.
Why use a Flow Rate Converter?
Flow rate conversion is essential in fluid mechanics, hydraulic engineering, and process design. Different industries and regions use different flow rate units - metric units like liters per second and cubic meters per hour, imperial units like gallons per minute and cubic feet per minute. This tool eliminates conversion errors and saves time when designing pumps, pipes, HVAC systems, and other fluid handling equipment.
Who is it for?
This tool is perfect for mechanical engineers, hydraulic engineers, HVAC technicians, process engineers, plumbers, pump designers, students studying fluid mechanics, and professionals working with fluid flow systems who need accurate flow rate unit conversions.
How to use the tool
Enter the flow rate value you want to convert in the input field
Select the source unit from the dropdown (liters/sec, gallons/min, etc.)
Choose the target unit you want to convert to
Click 'Convert' to see the result instantly
Use the swap button to quickly reverse the conversion direction
Copy the result or use the clear button to start over
Frequently Asked Questions
How do I convert flow rate units?
Enter the source value, pick the 'from' and 'to' units, and the result appears instantly. Supports m³/s (SI), L/s, L/min, L/h, gal/min (gpm, US), gal/min (UK), ft³/min (cfm), ft³/s (cfs). Copy the converted value to clipboard. Conversion runs entirely in your browser — values never leave the device. Decimal precision is configurable; default shows 4-6 significant figures, appropriate for most use cases. For scientific work needing more precision, increase the decimal places in the settings.
What flow rate units does this converter support?
m³/s (SI), L/s, L/min, L/h, gal/min (gpm, US), gal/min (UK), ft³/min (cfm), ft³/s (cfs). The set covers SI base and derived units, common imperial/US-customary units, and domain-specific units where relevant. SI prefixes (k, M, G, m, μ, n) apply where applicable. For any unit not in the list that you need converted, mention it via feedback — the unit set evolves based on user requests.
How accurate is the flow rate conversion?
Conversions use exact internationally-defined factors where they exist — no rounding loss at the math level. Conversion factors use the exact gallon definitions. For gas-flow at non-standard conditions, normalize to 'standard cubic feet per minute' (scfm) accounting for pressure and temperature — this tool assumes constant conditions. Output precision is bounded by the displayed decimal places (configurable, typically 4-6 by default). For extreme precision needs (scientific publications), increase the displayed decimals to match your significant-figure requirements.
What's the formula to convert gallons per minute (US gpm) to litres per minute?
L/min = US gpm × 3.785. HVAC sizing (ft³/min or cfm for airflow, gpm for pumps), plumbing (gpm for water flow), industrial process engineering (m³/s for large pipelines, L/min for chemical dosing), automotive fuel-injection (mL/s per injector). For other flow rate-unit pairs, the tool applies the appropriate exact conversion factor automatically — no manual formula needed. The conversion preserves precision to the displayed decimal places; choose precision to match your downstream use (engineering specs typically need 3-4 significant figures; scientific work may need more).
What's the key accuracy caveat for flow rate conversion?
**US gallons vs UK gallons matter for flow rate too** — same gallon ambiguity as [Volume Converter](/tools/volume-converter/). A '50 gpm' pump in the US delivers ~189 L/min; a '50 gpm' pump in the UK delivers ~227 L/min. For HVAC and plumbing specs, always specify which gallon. **Mass flow vs volume flow** — this converter measures volume flow (m³/s, L/s); for fluids of varying density (compressed gases at different pressures), mass flow (kg/s) may be more useful.
What's a common real-world use case for flow rate conversion?
HVAC sizing (ft³/min or cfm for airflow, gpm for pumps), plumbing (gpm for water flow), industrial process engineering (m³/s for large pipelines, L/min for chemical dosing), automotive fuel-injection (mL/s per injector).
What flow rate units are commonly confused?
**US gpm vs UK gpm** — ~20% difference per the gallon difference. **cfm (cubic feet per minute) vs cfs** — cfm is 60× smaller than cfs. **gpm vs L/min** — practical pump-spec conversion factor ~3.785 (US) or ~4.546 (UK).
How do I handle very large or very small flow rate values?
Use SI prefixes for clean scaling: kilo (10³), mega (10⁶), giga (10⁹), milli (10⁻³), micro (10⁻⁶), nano (10⁻⁹). For values beyond standard prefixes, the tool displays results in scientific notation (e.g. 1.23e+15) for readability. Conversion factors use the exact gallon definitions. For gas-flow at non-standard conditions, normalize to 'standard cubic feet per minute' (scfm) accounting for pressure and temperature — this tool assumes constant conditions. For data interchange to other tools, copy the raw value; for human readers, use the precision that matches the context.
Share This Tool
Found this tool helpful? Share it with others who might benefit from it!
💡 Help others discover useful tools! Sharing helps us keep these tools free and accessible to everyone.