LPM to CFM Converter
1 L/min = 0.0353146667 CFM. The conversion chain: 1 L = 0.001 m³ exactly (by SI definition), 1 m³ = 35.314666721 ft³ (since 1 ft = 0.3048 m exactly), so 1 L/min = 0.001 ×...
Formula
Source: NIST SP 811, ISO 80000-4 | Last reviewed: June 27, 2026
Examples
1 L/min
= 0.0353 CFM
1 LPM = 0.0353 CFM
28.32 L/min
= 1 CFM
28.32 LPM = 1 CFM (reverse equivalence)
100 L/min
= 3.53 CFM
100 LPM = 3.53 CFM, laboratory gas manifold flow
500 L/min
= 17.66 CFM
500 LPM = 17.7 CFM, medium process gas flow
Quick Reference Table
| L/min | CFM | Typical Application |
|---|---|---|
| 1 | 0.0353 | Very small lab flow |
| 5 | 0.177 | Adult O₂ therapy flow |
| 10 | 0.353 | Small lab gas manifold |
| 28.32 | 1 | 1 CFM exactly |
| 50 | 1.77 | Medium lab / small process flow |
| 100 | 3.53 | Lab gas manifold / medical ward |
| 500 | 17.7 | Medium process gas flow |
| 1000 | 35.3 | Large process / CIP system flow |
Where is this used?
The conversion chain: 1 L = 0.001 m³ exactly (by SI definition), 1 m³ = 35.314666721 ft³ (since 1 ft = 0.3048 m exactly), so 1 L/min = 0.001 × 35.314666721 = 0.0353146667 CFM.
The time unit (per minute) is the same, so the conversion is purely volumetric.
LPM (liters per minute) is the universal mid-range flow unit for laboratory, medical, and small industrial gas and liquid flow applications.
In contrast, CFM is the universal US airflow and gas flow unit, but it's a much larger unit: 1 CFM = 28.32 LPM.
So LPM-to-CFM conversions typically deal with fractional CFM values, a 50 LPM laboratory gas flow is only 1.77 CFM, less than a typical bathroom exhaust fan.
The conversion is essential in applications where European-manufactured equipment rated in LPM must be integrated into US systems designed in CFM.
Medical oxygen flowmeters and anesthesia machines worldwide use L/min, a typical adult oxygen therapy flow of 5 L/min = 0.177 CFM.
A US hospital's medical gas piping system is sized in CFM (per NFPA 99, Health Care Facilities Code), and the conversion from the L/min terminal unit flow to CFM for piping design is a common calculation: 100 L/min of O₂ at a patient station = 3.53 CFM, and a 20-station ward at 5 L/min each (100 L/min total) requires 3.53 CFM of oxygen piping capacity.
Laboratory gas chromatography and mass spectrometry carrier gas flows are in mL/min (1-50 mL/min), but the supply system (gas cylinders, manifolds, bulk tanks) is sized in CFM or SCFH.
A laboratory with 10 GCs, each consuming 30 mL/min of helium carrier gas, draws 300 mL/min = 0.3 L/min = 0.0106 CFM of helium, a trivial flow for the supply system, but the purge requirements during column changes and bakeout may be 100× higher.
Converting LPM to CFM also appears in beverage and pharmaceutical process engineering: a clean-in-place (CIP) spray ball requires 150 L/min of cleaning solution flow = 5.30 CFM, and the US CIP supply pump (sized in GPM) must deliver at least that much.
The conversion chain LPM → CFM → GPM involves multiple steps but is routine in international food and pharma engineering.
Real-World Usage Scenarios
International pharmaceutical cleanroom design
A European pharmaceutical engineering firm designs a new GMP cleanroom facility in the US. The cleanroom requires a specific air change rate (ACH) of 30/hr for ISO Class 7 cleanliness. The room dimensions: 12 m × 8 m × 3 m = 288 m³. Air flow required: 288 × 30 = 8,640 m³/hr = 144 m³/min = 5,086 CFM. The European-designed HVAC system uses L/min as the base unit for terminal flow control at each HEPA filter array. The US design team verifies the terminal air flows: each of 12 HEPA filter arrays must supply 8,640 / 12 = 720 m³/hr = 12 m³/min = 424 CFM total per array. The LPM-to-CFM conversion is performed at the terminal unit specification (each HEPA filter has a flow control valve that must be set in L/min, but the verification test report shows airflow in CFM). A 1% error in the conversion (× 0.03531 instead of 0.035315) corresponds to about 4 CFM per array, meaningful for the cleanroom qualification testing where the ACH must be ±10% of design.
Industry Standards Referenced
Frequently Asked Questions
What's the relationship between LPM, CFM, and GPM?
1 CFM = 28.32 LPM. 1 GPM = 3.785 LPM. So CFM and GPM are in a fixed ratio: 1 CFM = 28.32 / 3.785 = 7.481 GPM (for US gallons). The LPM scale sits between the very small lab flow scale (mL/min) and the large industrial flow scale (m³/h). For gas flows, LPM typically refers to flow at the measurement conditions (actual), not standard conditions, unless specified as 'NL/min' (normal liters per minute, at 0°C, 1 atm) or 'SL/min' (standard liters per minute, at reference conditions).
What does this converter do?
This converter performs the unit conversion at standard conditions using the exact conversion factor. The result is displayed with appropriate precision for engineering use.
How accurate is the conversion?
The conversion factor used is exact or to four significant figures depending on the units. For most engineering calculations, the precision is more than sufficient. For precision work, consult the relevant NIST or ISO standards referenced on this page.
Reviewed for accuracy
Verified against international volume conversion standards · Last reviewed: June 27, 2026
All calculations are for reference only. Always verify with manufacturer data and a qualified engineer for critical applications. Learn about our editorial process.