CFM to LPM Calculator

Cubic Feet Per Minute to Liters Per Minute

CFM to LPM converts cubic feet per minute into liters per minute. Both units measure volumetric airflow. CFM is common in North American HVAC, ventilation, duct, fan, and air compressor documents, while LPM is common in metric instruments, laboratory gas flow, pneumatic controls, and international project documentation.

Key Engineering Entities

This page uses entities such as CFM, LPM, cubic feet per minute, liters per minute, HVAC, ventilation, air compressors, duct systems, ASHRAE, SMACNA, AMCA, CAGI, ISO 1217, SCFM, ACFM, SLPM, and NLPM.

Convert CFM to LPM Instantly

The CFM to LPM calculator above requests an airflow value in cubic feet per minute and returns the equivalent liters per minute. It is useful when a fan schedule, compressor datasheet, duct-balancing report, or US airflow specification must be entered into metric equipment or documentation.

Default example: 10 CFM = 283.17 LPM.

Direct Volume Flow Conversion

To convert CFM to LPM, multiply the CFM value by 28.3168466. This factor comes from the relationship between cubic feet and liters: one cubic foot contains about 28.3168466 liters.

This is a direct unit conversion. It does not correct airflow for pressure, temperature, humidity, gas composition, altitude, or standard reference conditions.

Two Airflow Units, One Physical Flow

Cubic feet per minute to liters per minute means changing the airflow unit without changing the flow itself. CFM appears in HVAC, ventilation, duct, fan, and compressor specifications. LPM appears on metric flow meters, laboratory gas panels, medical gas equipment, and pneumatic regulators.

Common Entity Context

CFM is common in ASHRAE ventilation schedules, AMCA fan data, SMACNA duct design, and CAGI compressed-air documents. LPM is common in metric instrumentation, ISO documentation, lab gas systems, and small airflow measurement.

Worked Calculation

For an airflow reading of 25 CFM, calculate LPM as 25 x 28.3168466 = 707.921 LPM. Use this when a CFM fan, duct, or compressor value must be compared with metric LPM equipment.

25 CFM = 707.92 LPM.

Exact Practical Value

1 CFM = 28.3168466 LPM. Rounded for fast field checks, 1 CFM is about 28.317 LPM, and 10 CFM is about 283.17 LPM.

Reverse Value

1 LPM = 0.0353147 CFM. Use the reverse factor when metric LPM airflow must be converted back into CFM.

Why the Factor Works

One cubic foot contains about 28.3168466 liters. Because CFM is cubic feet per minute, multiplying by 28.3168466 gives liters per minute.

Quick Airflow Chart

The chart below uses LPM = CFM x 28.3168466. It supports airflow conversion for HVAC, ventilation, air compressors, pneumatic tools, gas-flow meters, and duct systems.

Example for a Fan Schedule

A ventilation fan is rated at 75 CFM. To convert it to LPM, multiply 75 by 28.3168466. The result is 2123.763 LPM. This helps compare the fan with metric airflow instruments or an international project schedule.

75 CFM x 28.3168466 = 2123.763 LPM.

Using CFM as an Airflow Unit

CFM to air flow rate usually means expressing a US customary airflow value in a metric unit such as LPM. CFM is common for fans, grilles, diffusers, air compressors, and duct balancing, while LPM is useful for metric flow meters and control devices.

Airflow conversion does not replace airflow design. Fan static pressure, duct velocity, pressure drop, air changes per hour, and equipment selection still require separate engineering checks.

CFM, SCFM, SLPM, and NLPM

CFM to standard LPM is not always the same as direct CFM to LPM. Standard liters per minute may be written as SLPM or NLPM, depending on the reference standard. SCFM, SLPM, and NLPM depend on pressure and temperature reference conditions.

Entity Notes

Compressed-air and gas-flow documents may reference ISO 1217, CAGI, SCFM, ACFM, FAD, inlet pressure, atmospheric pressure, inlet temperature, and relative humidity. Confirm the standard basis before treating CFM as standard LPM.

Fresh Air and Exhaust Air

CFM to LPM for ventilation is used when outdoor air, exhaust air, or room ventilation data is specified in CFM but metric reporting or instrumentation needs LPM. Ventilation work commonly references ASHRAE 62.1, ASHRAE 62.2, occupancy, outdoor air rate, exhaust air rate, and air changes per hour.

100 CFM ventilation air = 2831.685 LPM.

Air Handlers, VAV Boxes, Fans, and Diffusers

CFM to LPM for HVAC helps convert air-handler, VAV box, fan coil, grille, diffuser, supply air, return air, outside air, and exhaust air values into metric documentation. HVAC entities include ASHRAE, AHRI, AMCA, fan static pressure, duct velocity, balancing reports, and equipment submittals.

Use the calculator for the unit conversion, then verify design performance against the project airflow schedule and manufacturer data.

Compressed Air and Pneumatic Tools

CFM to LPM for air compressors is used when compressor output or tool demand is listed in CFM and a metric flow value is needed. Common entities include Atlas Copco, Ingersoll Rand, Kaeser, Sullair, CAGI, ISO 1217, receiver tank, free air delivery, SCFM, ACFM, FAD, and working pressure.

For compressor sizing, confirm the airflow basis before converting. SCFM, ACFM, FAD, and displaced volume can produce different practical meanings.

Duct Balancing and Commissioning

CFM to LPM for duct systems helps translate branch airflow, diffuser airflow, grille airflow, and exhaust airflow from CFM into metric LPM. Duct design commonly references SMACNA, ASHRAE, duct velocity, friction loss, static pressure, balancing dampers, and air terminals.

After converting CFM to LPM, check duct velocity and pressure drop separately because unit conversion alone does not validate duct performance.

Reverse Conversion Example

A 500 LPM airflow reading equals 500 x 0.0353147 = 17.657 CFM. Use this when metric airflow must be compared with CFM-based fan, duct, or compressor data.

Use CFM, LPM, SCFM, and SLPM Consistently

Airflow conversion keeps fan schedules, compressor datasheets, flow meters, pneumatic equipment, and duct measurements in the same unit system. CFM and LPM are both volumetric flow units, while SCFM, SLPM, and NLPM add standard-condition assumptions.

For engineering-critical applications, verify the converted value against manufacturer data, project specifications, and the required standard pressure and temperature conditions.