CFM to LPS Converter
Convert airflow instantly from cubic feet per minute (CFM) to liters per second (LPS) using our quick online CFM to LPS converter. In commercial HVAC design, converting volumetric airflow between Imperial and metric units is a daily task when balancing air handling units, selecting terminal diffusers, and matching project specifications across different regional standards. Whether you are reviewing submittal data, calculating duct dimensions, or verifying field measurements, accuracy is essential to keep static pressure drop and system noise within design limits. This tool delivers fast, exact conversions so mechanical engineers, MEP draftsmen, and HVAC contractors can verify airflow figures in seconds and keep engineering submittals moving forward smoothly without manual calculation errors.
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Move from airflow checks to project planning
An airflow conversion is one part of HVAC design. DuctArchitect keeps duct sizing, heat-load calculations, calculation reports, and project work together so contractors and consultants can carry results into the next project step.
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Heat Load Calculator: Review heating and cooling requirements alongside airflow data.
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CFM to L/s formula
L/s = CFM × 0.47194744
CFM = L/s ÷ 0.47194744
The factor is 0.47194744 L/s for each 1 CFM. Going the other way, 1 L/s is 2.11888 CFM.
CFM to LPS Conversion Chart
The chart below provides quick reference values for standard airflow figures commonly used in duct sizing and terminal unit selection. It allows immediate verification of equipment capacities without manual calculations.
| CFM | L/s | Common Application |
|---|---|---|
| 100 | 47.1947 | Small Exhaust / Supply Diffuser |
| 250 | 117.987 | Standard Office Supply Grille |
| 500 | 235.974 | Small Fan Coil Unit (FCU) |
| 1,000 | 471.947 | Medium FCU / Small Air Handling Unit |
| 2,000 | 943.895 | Commercial Air Handling Unit (AHU) |
| 5,000 | 2,359.74 | Large AHU / Primary Air Unit |
| 10,000 | 4,719.47 | Central Plant Air Distribution |
Where this conversion is used
Litres per second is the usual airflow unit in ventilation guides and consultant specifications that follow British and European practice, which is common on Gulf projects. Fresh air rates per person, toilet and kitchen extract rates and VAV box schedules are often given in L/s, while equipment selected from US catalogues is rated in CFM.
Worked example
A fan coil unit is rated at 350 CFM and the consultant's equipment schedule asks for airflow in L/s.
350 CFM × 0.47194744 = 165.182 L/s
Enter about 165.2 L/s in the schedule.
Common mistakes
- Confusing L/s with m³/h. One litre per second is 3,600 litres per hour, so the L/s figure is much smaller than the m³/h figure for the same airflow.
- Dividing when you should multiply. The L/s number is always smaller than the CFM number, a little under half of it.
- Converting a per person fresh air rate and forgetting the occupancy. Convert the rate first, then multiply by the number of people.
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Frequently asked questions
How do I convert CFM to L/s?
Multiply the CFM value by 0.47194744 to get L/s. The CFM to LPS formula is L/s = CFM × 0.47194744.
How many liters are in 1 CFM?
One CFM equals approximately 0.471947 litres per second, or 28.3168 litres per minute. This is a volume flow rate, not a total volume.
Is L/s the same as LPS?
Yes. L/s and LPS commonly refer to litres per second, although L/s is the clearer notation for technical documents.
How does the CFM to LPS converter work?
It applies a fixed unit conversion factor to the airflow value. Multiply CFM by 0.47194744 for L/s, or multiply L/s by approximately 2.11888 for CFM.
Should I round results before specifying equipment?
Use rounding for quick checks only, and retain the precision required by project specifications and manufacturer data. Confirm the expected airflow unit before approving a schedule.
How do I check CFM to LPS for AHU airflow?
Multiply the AHU's stated CFM by 0.47194744 to get L/s, then compare the result with the equipment schedule. This conversion does not confirm AHU capacity or prove that the system design is suitable.
How do I check CFM to LPS for FCU airflow?
Multiply the FCU's stated CFM by 0.47194744 to get L/s, then compare the result with the submittal or schedule. Check the selected unit and operating conditions separately.
Can I convert CFM to litres per hour?
Yes. Multiply CFM by approximately 1,699.01 to obtain litres per hour. This changes the unit of the airflow rate; it does not assess ventilation requirements.
What should airflow calculations for UAE projects include?
An HVAC airflow calculator UAE contractors use should label both units and apply the fixed conversion factor. UAE summers are hot and humid in many areas, so converted airflow should be checked alongside project load, ventilation criteria, and manufacturer data.
Does the conversion factor change for Saudi Arabia projects?
No, the factor stays the same. A CFM to LPS calculator Saudi Arabia contractors use should apply 1 CFM = 0.47194744 L/s. Saudi Arabia has regional climate differences, so cooling and ventilation design still require local project data.
What should Oman HVAC teams check before converting airflow?
The HVAC airflow conversion Oman project teams use should start with the units shown in the equipment schedule or submittal. Oman has regional climate differences, so local design conditions and manufacturer data must be checked separately from the unit conversion.
How do I calculate CFM in HVAC?
CFM in HVAC is calculated from the airflow requirement for the application. Depending on the design, the calculation may use ventilation criteria, air-change requirements, room load calculations, or equipment specifications. This converter changes units but does not determine the required CFM.