Flow Rate Converter Online — Free Flow Rate Converter Tool
CodexFuse Team · 2026-10-29T19:09:28.057Z · 9 min read min read
Convert GPM to L/min, CFM to m³/h and more instantly with the free CodexFuse flow rate converter, with all 10 units shown at once.
A flow rate converter turns a volume-flow measurement from one unit into another, so a pump rated in gallons per minute can be compared directly with a specification written in litres per minute. You enter one value, choose the units, and the tool shows the same flow in every equivalent unit.
That single step prevents the most common flow-rate mistake: comparing two numbers that look alike but are measured differently. A pump, a fan, and an irrigation line can all be described correctly and still be impossible to compare until their units match.
What is a flow rate, and why do its units cause so many errors?
A flow rate is the volume of fluid or air that passes a point in a given time, such as litres per minute, cubic metres per hour, US gallons per minute (GPM), or cubic feet per minute (CFM). The errors happen because different trades, countries, and manufacturers use different units for the same physical quantity, so 12 in one unit is not 12 in another. Converting first, before buying or sizing anything, is what makes the numbers comparable.
Three unit families cause most confusion:
- Litres and cubic metres: the metric family, common in specifications, building services, and most of the world outside the United States.
- US gallons: the imperial-style family used widely in American pumps, pools, and irrigation equipment, where 1 US gallon is 3.785411784 litres.
- Cubic feet: the family used for air movement, especially ventilation and HVAC, where 1 cubic foot is 28.31684659 litres.
Watch the gallon trap: a US gallon and an imperial gallon differ, so a converter that does not state its gallon can mislead you. The CodexFuse tool uses US gallons (GPM and GPH).
How do you use the CodexFuse flow rate converter?
You use the CodexFuse flow rate converter by entering your value, choosing the unit it is in, choosing the unit you want, and reading the result alongside the same value in all ten units. The whole job takes under a minute, and there is nothing to install.
The steps, verified against the live tool page, are:
- Enter your flow rate value: type the number exactly as it appears on the pump, fan, or specification sheet, decimals included.
- Choose the from and to units: pick from L/s, L/min, L/h, m³/s, m³/min, m³/h, GPM, GPH, ft³/s, and CFM.
- Read the result: the converted value appears immediately, with the same flow shown in all nine other units below it.
- Swap or copy as needed: use the swap button to reverse the direction in one click, or copy the result straight into a quote, order, or specification.
Convert before you round. Enter the full datasheet figure, read the exact converted value, and only then round to the precision your supplier or specification actually needs. Rounding first and converting second compounds the error.
Worked example: checking a pump and a fan on the same job
Dan is a fictional heating and ventilation engineer fitting out a small workshop. He has two checks to make before ordering, and both arrive in the wrong units for the paperwork he must file.
First, the circulating pump he wants is rated at 8 GPM, but the boiler manufacturer's specification is written as 30 L/min minimum. Dan opens the flow rate converter, enters 8, selects GPM as the from unit and L/min as the to unit, and reads 30.28 L/min. The pump clears the requirement, but only just, so he notes the slim margin rather than assuming a comfortable surplus.
Second, the ventilation fan is rated at 320 CFM, while the ductwork specification is written in cubic metres per hour. Dan enters 320, converts CFM to m³/h, and gets around 543.7 m³/h. That figure goes directly into his submission, with no hand arithmetic and no second-guessing about whether a cubic foot is 28 litres or 30.
The whole check takes about two minutes, and Dan's real output is a pump decision he can defend, a fan figure he can file, and a margin (0.28 L/min) he knows to watch.
What are the most useful flow rate conversions?
Most everyday conversions reduce to a handful of factors. Knowing them helps you sense-check a tool result at a glance, even if you still let the converter do the precise arithmetic.
| Conversion | Factor | Example |
|---|---|---|
| GPM to L/min | Multiply by 3.78541 | 10 GPM = 37.85 L/min |
| L/min to GPM | Multiply by 0.26417 | 100 L/min = 26.42 GPM |
| m³/h to L/min | Multiply by 16.6667 | 5 m³/h = 83.33 L/min |
| CFM to L/min | Multiply by 28.3168 | 100 CFM = 2,831.68 L/min |
| CFM to m³/h | Multiply by 1.69901 | 100 CFM = 169.90 m³/h |
For tank and pond jobs, a fish tank volume calculator pairs well with this tool, since those jobs need both total volume and pump flow rate. A cooking measurement converter handles the same mismatch at kitchen scale.
If mismatched units, scattered tools, and a pile of separate hosting, email, and security subscriptions are eating your working week, move the lot to CodexFuse: one fully managed, all-in-one IT platform on pay-as-you-go credits, with no subscriptions and no server babysitting.
Get Started with CodexFuseWhat does a flow rate converter not do?
A flow rate converter changes units; it does not check whether a flow is adequate, safe, or legal for your system. That distinction matters, and honest tools say so plainly.
- It does not size your system: converting 8 GPM to 30.28 L/min tells you nothing about pipe friction, pump head, or pressure loss. Those need a separate calculation for your pipe length, diameter, and fittings.
- It does not convert mass or molar flow: this tool converts volume flow only. Mass flow in kg/s and molar flow in mol/s need a density or molar mass, so they are separate conversions entirely.
- It does not validate a datasheet: if the manufacturer's rating is wrong, optimistic, or measured under different conditions, the converter will faithfully convert the wrong number. Cross-check ratings that look too good to be true.
- It does not replace regulations: ventilation rates, irrigation limits, and discharge rules are set by codes and permits, not by arithmetic. Convert the numbers, then check them against the rule that applies.
Never order a pump or fan on a converted figure alone when the margin is tight. Dan's pump cleared its specification by 0.28 L/min, which is within rounding and measurement tolerance. In that situation, confirm the rating with the supplier or choose the next size up, rather than discovering the shortfall after installation.
When is a flow rate converter the right tool, and when is it not?
Use a flow rate converter whenever two documents describe the same flow in different units, whenever you are ordering equipment from a supplier who uses another unit system, or whenever you need to file a figure in a unit you did not receive it in. Those are conversion jobs, and a converter is exactly the right instrument.
Do not use it as a substitute for system design. If you are choosing pipe diameters, calculating pump head, or checking a flow against a safety standard, you need the engineering calculation behind the number, not just the number in a new unit.
If you regularly convert areas as well as flows, the area converter guide covers plot sizes in acres, hectares, and square feet. For unit conversions in general, the feet to metres guide is a handy companion.
How does CodexFuse fit a business that lives on conversions like this?
CodexFuse is an all-in-one, fully managed IT platform that runs on credits, with no subscriptions and no lock-ins. For a tradesperson or small business, the practical workflow is straightforward: create an account, add credits only for the services you actually use, and bring your website, business email, security, and backups under one managed roof instead of juggling separate providers.
The benefit is the same one a converter gives you: one consistent system instead of constant translation. Start with the service that causes the most friction, typically hosting or business email, migrate that first, and then consolidate the rest once you trust the setup.
Frequently Asked Questions
How do I convert GPM to L/min?
Multiply GPM by 3.785411784, because 1 US gallon is 3.785411784 litres. So 10 GPM is 37.85 L/min, and 8 GPM is 30.28 L/min. The reverse is 1 L/min = 0.2641720524 GPM, so 100 L/min is 26.42 GPM.
How many L/min is 1 m³/h?
1 m³/h is 16.66666667 L/min, because one cubic metre is 1,000 litres spread over 60 minutes. So 5 m³/h is 83.33 L/min, and 1 m³/h is around 4.40 GPM.
What is CFM in L/min?
1 CFM is 28.31684659 L/min, because one cubic foot is 28.31684659 litres. So 100 CFM is 2,831.68 L/min, and 320 CFM is around 9,061.39 L/min, or about 543.7 m³/h.
Does the converter handle mass flow?
No. It converts volume flow only, covering litres, cubic metres, US gallons, and cubic feet per second, minute, or hour. Mass flow in kg/s needs a fluid density, and molar flow needs a molar mass, so those require separate tools.
Is the CodexFuse flow rate converter free?
Yes. It is free, runs entirely in your browser, and shows all ten units at once, with a swap button and a copy option. There is no file to upload and no software to install.
Which gallon does the converter use?
It uses the US gallon, so GPM means US gallons per minute. If your equipment is rated in imperial gallons, convert that figure to US gallons first, or your result will be off by around 20 percent.
Convert the Number, Then Fix the Fragmentation Behind It
A flow rate converter solves a small, sharp problem: two numbers that cannot be compared until they share a unit. Enter the value, pick the units, read all ten equivalents, and file a figure you can defend. Keep the limits in mind, especially the tight-margin warning, and do not ask a converter to do an engineer's sizing job.
Then apply the same thinking to the rest of your business. If your website, email, security, and backups are scattered across subscriptions, move them to CodexFuse: one fully managed, all-in-one platform on pay-as-you-go credits. Get started with CodexFuse today.