CFM to LPM Converter

Convert cubic feet per minute (CFM) to litres per minute (LPM) for air flow rate measurements. This converter works both ways—enter values in either field to get instant results. Whether you’re specifying HVAC systems, setting up compressors, or working with ventilation equipment, this page gives you the numbers you need.

Cubic Feet Per Minute (CFM)

Litres Per Minute (LPM)

Quick Conversions:

Conversion Formula

The conversion between CFM and LPM relies on the relationship between cubic feet and litres. Since both units measure flow per minute, the time component stays constant.

LPM = CFM × 28.316847

CFM = LPM × 0.0353147

Step-by-Step Conversion

Converting CFM to LPM:

Take your CFM value
Multiply by 28.316847
The result is your LPM value
Example: 10 CFM × 28.316847 = 283.16847 LPM

Converting LPM to CFM:

Take your LPM value
Multiply by 0.0353147
The result is your CFM value
Example: 500 LPM × 0.0353147 = 17.66 CFM

CFM to LPM Conversion Table

Common air flow rates converted from cubic feet per minute to litres per minute:

CFM	LPM
0.5	14.16
1	28.32
2	56.63
5	141.58
10	283.17
15	424.75
20	566.34
25	707.92
50	1,415.84
75	2,123.76
100	2,831.68
150	4,247.53
200	5,663.37
250	7,079.21
500	14,158.42
1,000	28,316.85

LPM to CFM Conversion Table

Litres per minute to cubic feet per minute conversions for common flow rates:

LPM	CFM
10	0.35
50	1.77
100	3.53
200	7.06
500	17.66
750	26.49
1,000	35.31
1,500	52.97
2,000	70.63
2,500	88.29
5,000	176.57
7,500	264.86
10,000	353.15

Where You’ll Use These Conversions

Air flow measurements pop up across various industries and settings. Here’s where CFM and LPM conversions matter most:

HVAC Systems

Heating, ventilation, and air conditioning specs often mix imperial and metric units. British engineers need both when working with international equipment or consulting European standards.

Compressed Air Equipment

Compressors, pneumatic machinery, and air-powered machinery require precise flow rates. Many European manufacturers rate equipment in LPM whilst UK workshops traditionally use CFM.

Cleanrooms and Laboratories

Controlled environments demand exact air flow measurements. Pharmaceutical facilities and research labs follow international protocols that may specify either unit.

Industrial Ventilation

Factories, workshops, and manufacturing plants need proper air exchange rates for worker safety. Regulations and equipment manuals might reference either measurement system.

Units of Flow Rate Conversions

CFM and LPM aren’t the only flow rate units you’ll encounter. Here’s how they compare to other common measurements:

Unit	Abbreviation	Equivalent to 1 CFM	Equivalent to 1 LPM
Cubic Feet per Minute	CFM or ft³/min	1	0.0353
Litres per Minute	LPM or L/min	28.3168	1
Cubic Metres per Hour	m³/h	1.699	0.06
Litres per Second	L/s	0.472	0.0167
Gallons per Minute (US)	GPM	7.481	0.264
Gallons per Minute (UK)	GPM (UK)	6.229	0.220

Everyday Situations

You might encounter these conversions in various scenarios:

Ordering a workshop compressor: The supplier’s catalogue lists output in CFM, but the pneumatic machinery you’re connecting requires 850 LPM minimum. Convert to confirm compatibility before purchasing.
Ventilation compliance: Building regulations specify 15 LPM per person for office spaces. Your 200-person office needs proper air handling, so you calculate the CFM requirement for the ventilation system.
Aquarium aeration: Fish tank air pumps from American retailers show CFM ratings, whilst European models use LPM. You need to compare specifications to choose the right pump for your tank size.
Paint booth installation: Safety standards require specific air changes per hour. The booth volume is in cubic metres, but the available fans are rated in CFM—multiple conversions needed to verify compliance.
Medical equipment setup: Respiratory devices and anaesthesia machines might use either unit depending on manufacturer origin. Hospital technicians convert between them when servicing equipment from different suppliers.

Metric vs Imperial in Air Flow

The choice between CFM and LPM often depends on geography and industry tradition. American and some British industries favour CFM, reflecting the imperial system’s historical dominance in engineering. Meanwhile, European manufacturers and modern international standards lean towards LPM and other metric measurements.

The UK sits in an interesting position. Whilst officially metric, many industries still work with imperial units for historical equipment and compatibility with American partners. HVAC professionals routinely switch between both systems depending on the project source and equipment origin.

This dual-system reality makes conversion skills essential. You can’t rely on everything being in one unit, especially when collaborating internationally or working with equipment from various manufacturers.

FAQs

What’s the exact conversion factor between CFM and LPM?

One cubic foot per minute equals 28.316847 litres per minute. For most applications, rounding to 28.32 gives sufficient accuracy. Going the other way, 1 LPM = 0.0353147 CFM.

Can I use this converter for liquids as well as gases?

Yes, the conversion works for any fluid. The units measure volumetric flow rate regardless of what’s flowing. However, remember that system behaviour differs between liquids and gases due to compressibility.

Why do compressor specs sometimes show different CFM ratings?

Compressors might list displacement CFM (theoretical maximum) versus free air delivery CFM (actual usable output). Always check which measurement you’re comparing. The conversion factor to LPM stays the same, but the practical number differs.

Does temperature or pressure affect these conversions?

The basic conversion between CFM and LPM is purely volumetric—it doesn’t change with conditions. However, when specifying compressed air systems, you’ll often see SCFM (standard cubic feet per minute) which references specific temperature and pressure. Make sure you’re comparing like with like.

Which unit should I use for my project?

Check what your equipment manuals, regulations, and suppliers use. If you’re working with international standards or European equipment, LPM might be more common. For American equipment or traditional British industries, CFM often appears. When in doubt, provide both measurements.

How precise do my conversions need to be?

For most HVAC and industrial applications, rounding to two decimal places suffices. Critical applications like cleanroom design or precision manufacturing might require more decimal places. Always consider your measurement uncertainty—your flow meter’s accuracy matters more than conversion precision.

What’s the difference between CFM and SCFM?

CFM measures actual volumetric flow at current conditions. SCFM (standard cubic feet per minute) measures flow normalised to standard conditions—typically 20°C and 1 atmosphere. SCFM allows fair comparison between systems operating at different pressures or temperatures.

Can I convert CFM to other metric flow units?

Absolutely. From LPM, you can easily convert to other metric units: divide by 60 for litres per second, or multiply by 0.06 for cubic metres per hour. Many engineering applications prefer cubic metres per hour for larger systems.