LPM to CFM Converter
Convert Liters Per Minute to Cubic Feet Per Minute Instantly
Conversion Formula
or: CFM = LPM ÷ 28.3168
or: LPM = CFM ÷ 0.0353146667
These formulas are based on the volumetric relationship where 1 cubic foot equals 28.3168 liters at standard atmospheric conditions.
Conversion Examples
Example 1: Converting 100 LPM to CFM
Given: 100 liters per minute
Calculation: 100 × 0.0353146667 = 3.53146667 CFM
Result: 100 LPM = 3.531 CFM
Example 2: Converting 5 CFM to LPM
Given: 5 cubic feet per minute
Calculation: 5 × 28.3168465934 = 141.584232967 LPM
Result: 5 CFM = 141.584 LPM
Example 3: Air Compressor Flow Rate
Scenario: An air compressor outputs 850 LPM. What is this in CFM?
Calculation: 850 × 0.0353146667 = 30.0174667 CFM
Result: 850 LPM = 30.017 CFM
LPM to CFM Conversion Chart
| LPM (Liters/Minute) | CFM (Cubic Feet/Minute) |
|---|
Popular Flow Rate Conversions
| LPM | CFM | Common Application |
|---|---|---|
| 10 | 0.353 | Small aquarium pump |
| 50 | 1.766 | Medical oxygen concentrator |
| 100 | 3.531 | HVAC ventilation fan |
| 250 | 8.829 | Industrial vacuum system |
| 500 | 17.657 | Medium air compressor |
| 1000 | 35.315 | Large HVAC system |
| 2000 | 70.629 | Industrial air compressor |
| 5000 | 176.573 | Large industrial blower |
Related Flow Rate Units
You can also convert LPM and CFM to these other flow rate units:
Applications of LPM and CFM
HVAC Systems
Flow rate measurements are critical for designing and maintaining heating, ventilation, and air conditioning systems. CFM is commonly used in North America for specifying air handler capacity, while LPM is standard in metric countries. Proper flow rates maintain indoor air quality and system efficiency.
Air Compressors
Air compressor output is rated in both LPM and CFM depending on the region. These ratings help users select the right compressor for pneumatic equipment like impact wrenches, spray guns, and sanders. Matching the flow rate prevents equipment underperformance.
Medical Equipment
Oxygen concentrators, ventilators, and anesthesia machines require precise flow rate specifications. Medical devices typically use LPM for oxygen delivery rates, but CFM conversions are needed when integrating with facility air supply systems.
Pumps and Water Systems
Water pump capacity is often rated in LPM, particularly for irrigation, aquariums, and industrial processes. Converting to CFM helps when comparing with air-moving equipment or designing hybrid systems.
Vacuum Systems
Industrial and commercial vacuum systems specify suction capacity in both metrics. Converting between LPM and CFM allows proper sizing for dust collection, material handling, and cleaning applications.
Automotive Performance
Engine air intake, turbocharger output, and exhaust flow measurements use both LPM and CFM. Performance tuners convert between units when sourcing international parts or comparing specifications.
Frequently Asked Questions
What is the difference between LPM and CFM?
LPM (liters per minute) is a metric unit measuring volumetric flow rate, while CFM (cubic feet per minute) is an imperial unit. Both measure the volume of gas or liquid passing through a point per minute. LPM is used in countries following the metric system, while CFM is common in the United States and other countries using imperial measurements.
How do I convert LPM to CFM?
To convert LPM to CFM, multiply the LPM value by 0.0353146667, or divide by 28.3168. For example, 100 LPM × 0.0353146667 = 3.531 CFM. This conversion factor comes from the relationship where 1 cubic foot equals 28.3168 liters.
Why do air compressors use different flow rate units?
Air compressor manufacturers target different regional markets. European and Asian manufacturers typically rate compressors in LPM, while North American brands use CFM. Both measure the same property—volumetric airflow—just in different unit systems.
Is CFM or LPM better for measuring airflow?
Neither unit is inherently better; the choice depends on your regional standards and equipment specifications. LPM is more precise for small flow rates and aligns with SI units, while CFM is traditional in American HVAC and industrial applications. Both units accurately measure volumetric flow when properly converted.
Does temperature affect LPM to CFM conversion?
The standard conversion assumes atmospheric conditions at sea level (20°C/68°F and 1 atmosphere pressure). Temperature and pressure changes affect gas volume, so actual flow rates may differ at altitude or extreme temperatures. For critical applications, use corrected flow rates based on actual conditions.
What CFM do I need for air compressor equipment?
Required CFM depends on your equipment: spray guns need 4-8 CFM, impact wrenches require 3-7 CFM, and sanders use 5-20 CFM. Add up all simultaneously used equipment and add 30% capacity margin. Convert manufacturer LPM ratings to CFM to verify compatibility.
Can I use this conversion for liquids and gases?
Yes, the volumetric conversion between LPM and CFM applies to both liquids and gases since it measures volume flow, not mass flow. However, density differences mean the same volumetric flow represents different mass flows. For mass flow calculations, consider fluid density separately.
What is SCFM vs CFM in relation to LPM?
SCFM (Standard Cubic Feet per Minute) measures flow at standardized conditions (typically 68°F, 36% humidity, sea level), while CFM measures actual flow at current conditions. When converting LPM, clarify whether you need SCFM or actual CFM, as the difference can be significant at altitude or in extreme temperatures.
Quick Reference Chart – CFM to LPM
| CFM (Cubic Feet/Minute) | LPM (Liters/Minute) |
|---|---|
| 0.5 | 14.158 |
| 1 | 28.317 |
| 2 | 56.634 |
| 3 | 84.950 |
| 5 | 141.584 |
| 10 | 283.168 |
| 15 | 424.753 |
| 20 | 566.337 |
| 25 | 707.921 |
| 50 | 1415.842 |
| 100 | 2831.685 |
| 200 | 5663.369 |
Tips for Accurate Flow Rate Measurements
- Verify Operating Conditions: Confirm whether ratings are at standard or actual conditions, as temperature and pressure affect gas volume significantly.
- Account for Pressure Drop: Flow rates decrease with distance and restrictions in piping systems. Size compressors and blowers with margin for system losses.
- Check Equipment Ratings: Air equipment lists minimum CFM requirements. Running below this causes poor performance even if pressure is adequate.
- Consider Duty Cycle: Compressor ratings often assume intermittent use. Continuous operation may require higher capacity than instantaneous calculations suggest.
- Use Proper Instruments: Flow meters, anemometers, and manometers provide accurate measurements. Manufacturer ratings may be optimistic.
- Match Unit Systems: When combining equipment from different regions, convert all specifications to the same unit system before sizing.