Calculator
What the Flow Rate Converter does
Flow Rate Converter: 1 L/s = 15.85032314 GPM, so multiply a litre per second value by 15.85032314 to get gallon per minute (US), or divide to go back. Example: 1 L/s = 15.85032314 GPM.
Supply Value, From and To and you get Result, How it was calculated and Reverse conversion back. Results refresh instantly, so trying variations costs nothing but a moment.
Having the exact factor matters more than a rough mental estimate. That is usually what brings anyone working across two measurement systems here.
This runs client-side, which means we never receive what you enter and could not retrieve it if asked.
The rest of this page documents each field, the method, and a worked example built from the values the flow rate converter loads by default.
What do the Flow Rate Converter fields mean?
The Flow Rate Converter uses 3 inputs. A complete set of starting values is loaded for you, so nothing is required before the first result appears.
| Field | What to enter | Default |
|---|---|---|
| Value | required | 1 |
| From | choose from Cubic metre per second (m³/s), Cubic metre per hour (m³/h), Litre per second (L/s), Litre per minute (L/min), Litre per hour (L/h) or Cubic foot per minute (CFM) | Litre per second (L/s) |
| To | choose from Cubic metre per second (m³/s), Cubic metre per hour (m³/h), Litre per second (L/s), Litre per minute (L/min), Litre per hour (L/h) or Cubic foot per minute (CFM) | Gallon per minute (US) (GPM) |
How does the Flow Rate Converter work?
Both units are converted through volumetric flow rate's base unit (m³/s), so any of the 8 units in the dropdowns can be paired in either direction without loss of accuracy.
The constants come from the SI brochure and the 1959 international yard-and-pound agreement. For quantities defined empirically rather than by treaty, the current CODATA or IAU value is used instead.
Worked example
These are the values the Flow Rate Converter loads by default, and the result it produces from them. This walkthrough uses the starting values, which means you can follow along without typing anything.
| Value | 1 |
|---|---|
| From | Litre per second (L/s) |
| To | Gallon per minute (US) (GPM) |
| Result | 15.85032314 GPM |
|---|---|
| How it was calculated | 1 L/s = 15.85032314 GPM, so 1 × 15.85032314 = 15.85032314 GPM |
| Reverse conversion | 0.063090196 L/s (if you meant 1 GPM) |
Volumetric flow rate
Flow rate measures how much fluid volume moves past a point per unit time, and different industries have settled on different conventional units: gallons per minute (GPM) in US plumbing and pumps, litres per minute or cubic metres per hour in most of the rest of the world, and cubic feet per minute (CFM) specifically for airflow in HVAC systems.
Worth knowing
- A typical US residential shower head is often rated around 2 to 2.5 gallons per minute (roughly 7.5 to 9.5 L/min) for water-efficiency purposes: a figure regulated in many jurisdictions to limit water waste.
- HVAC airflow specifications in CFM don’t convert directly to liquid flow-rate units like GPM without also knowing the specific context, since CFM specifically describes air (a gas) movement, typically for ventilation and cooling capacity rather than liquid plumbing.
- Industrial and municipal water systems typically report flow in cubic metres per hour or litres per second internationally, making this conversion practically necessary when comparing equipment specifications or usage data sourced from different countries.
Definitions: BIPM SI Brochure · NIST reference on units
How to use it
- Put Value.
- Pick a value for From: the options are Cubic metre per second (m³/s), Cubic metre per hour (m³/h), Litre per second (L/s), Litre per minute (L/min), Litre per hour (L/h) or Cubic foot per minute (CFM).
- Pick a value for To: the options are Cubic metre per second (m³/s), Cubic metre per hour (m³/h), Litre per second (L/s), Litre per minute (L/min), Litre per hour (L/h) or Cubic foot per minute (CFM).
- The output refreshes live, so you can stop as soon as the number looks right.
- The results panel then shows Result, How it was calculated and Reverse conversion.
- Share the link rather than a screenshot. It carries the values with it.
What this tool does not do
- Repeated conversions compound rounding, so convert once from the original value where possible.
- Factors use the internationally agreed definitions; some industries round them differently.
- The result reflects the moment you ran it; anything that changes over time is not tracked.
- Read the field labels once before trusting the answer; they specify the expected unit.
Frequently asked questions
Only Value, From and To. Each field is pre-filled with a sensible default, letting you treat it as a what-if tool rather than a data-entry form.
With the values loaded when the page opens, result comes out as 15.85032314 GPM. Change a value and the number is recomputed on the spot.
No. There is no upload step, no database, and nothing to delete afterwards.
It is free to use, with no premium tier holding back the useful parts.
It matches what you would get working it out by hand, with fewer opportunities to slip.