CFM to m³/h Converter
The conversion from cubic feet per minute (CFM) to cubic meters per hour (m³/h) derives from the fixed relationship between the cubic foot and the cubic meter. One cubic foot...
Formula
Source: Engineering Toolbox | Last reviewed: June 7, 2026
Examples
1 CFM
= 1.699 m³/h
1 CFM = 1.699 m³/h
100 CFM
= 169.9 m³/h
1000 CFM
= 1699 m³/h
Quick Reference Table
| CFM | m³/h |
|---|---|
| 10 | 16.99 |
| 50 | 84.95 |
| 100 | 169.9 |
| 400 | 679.6 |
| 1000 | 1699 |
| 2000 | 3398 |
Where is this used?
Air handling unit selection frequently crosses unit systems — a specification calling for 5,000 CFM of supply air corresponds to 8,495 m³/h, the value used when evaluating AHU selections from European manufacturers like Systemair, FlaktGroup, or TROX.
Exhaust fan sizing for industrial facilities follows the same pattern: a welding fume extraction system designed for 10 air changes per hour in an 80,000 ft³ shop yields 13,333 CFM exhaust, or 22,654 m³/h — the fan manufacturer's performance tables in m³/h must be checked against this value.
Cleanroom certification per ISO 14644-1 requires airflow expressed in m³/h to compute air change rates; a semiconductor fab with 50,000 CFM of recirculation air converts to 84,950 m³/h for the ISO compliance report.
Laboratory ventilation design for chemical fume hoods typically specifies 100 ft/min face velocity at a given hood opening area, producing a CFM requirement that must be converted to m³/h for European-sourced variable air volume (VAV) controls and exhaust fans.
In data center cooling, CRAC (computer room air conditioner) units may be rated in CFM by US manufacturers but integrated into a design that uses m³/h for chilled water and containment airflow balance calculations per ASHRAE TC 9.9 guidelines.
Pneumatic conveying systems for bulk solids (cement, flour, plastic pellets) use air velocity in m/s and pipe diameter to determine volumetric flow; when US field crews lay out piping in inches and CFM, the design engineer converts to m³/h to verify that conveying velocity remains in the correct transport regime.
Tunnel ventilation for road and rail tunnels — often international projects governed by EU directives — requires emergency smoke control airflow rates routinely specified in m³/h, while the jet fan and axial fan selections may originate from US manufacturers publishing performance data in CFM.
The converter supports these workflows by providing instant, error-free bidirectional conversion alongside L/min and L/s outputs for specialty applications.
Real-World Usage Scenarios
International Hospital HVAC Design
A US-based MEP firm is designing the HVAC system for a hospital expansion in Dubai, where authorities require submittals in SI units. The operating rooms require 20 ACH in a 5,000 ft³ volume, yielding 1,667 CFM supply air per OR suite. Converted: 1,667 × 1.69901 = 2,832 m³/h per suite. With 12 ORs, the central AHU must deliver 33,984 m³/h. The design team selects a European-manufactured AHU rated at 34,000 m³/h, confirming the CFM-to-m³/h conversion at every stage of the equipment schedule. The same conversion is applied to the HEPA filter housing specifications, which are sourced from a German supplier with pressure drop data published in Pa vs m³/h.
Industrial Paint Booth Ventilation
An automotive manufacturing plant installs a new paint spray booth requiring 100 ft/min face velocity across a 20 ft × 15 ft opening per NFPA 33. Airflow = 100 × 20 × 15 = 30,000 CFM. The exhaust fan manufacturer in Italy publishes performance curves in m³/h, so the engineer converts: 30,000 × 1.69901 = 50,970 m³/h. She selects two fans at 25,500 m³/h each for redundancy. The make-up air unit (also European) is sized at 51,000 m³/h with 80% recirculation — the 10,200 m³/h of fresh make-up air is cross-checked as 6,000 CFM to verify compliance with OSHA minimum ventilation rates.
Data Center Containment Airflow Balance
A colocation data center with hot-aisle containment has 200 server racks, each requiring 160 CFM of cooling airflow per kW of IT load. At an average rack density of 8 kW, the total cooling airflow requirement is 200 × 8 × 160 = 256,000 CFM. The facility uses CRAC units from a US manufacturer, but the chilled water plant serving them was designed by a European MEP firm in metric units: 256,000 × 1.69901 = 434,947 m³/h. The chilled water flow rate is derived from this airflow and the supply air temperature differential, then converted back to US GPM for the chiller selection. Every step of this cross-unit workflow relies on the accuracy of the 1.69901 conversion.
Common Mistakes to Avoid
Confusing CFM with SCFM or ACFM
CFM is a volumetric flow rate at actual conditions, while SCFM is corrected to standard conditions (typically 70°F and 14.7 psia). The 1.69901 conversion factor applies equally to both, but the underlying flow values differ significantly. A compressor rated at 100 SCFM delivers different actual CFM depending on inlet temperature and pressure. Always confirm whether your source uses CFM, SCFM, ACFM, or ICFM before converting.
Using the wrong conversion direction
A common spreadsheet error is multiplying when division is required or vice versa. To convert CFM to m³/h, multiply by 1.69901. To convert m³/h to CFM, divide by 1.69901 (or multiply by 0.5886). A quick sanity check: m³/h values are always larger than CFM values by approximately 70%. If your m³/h result is smaller than the CFM input, you have the direction reversed.
Neglecting duct leakage when converting design airflow
The CFM value at the fan discharge is higher than the CFM delivered to the space due to duct leakage. SMACNA allows leakage rates of 1-6% depending on duct pressure class and seal class. When converting design supply CFM to m³/h for equipment selection, use the fan-rated CFM (not room-level CFM) and apply the appropriate leakage factor per SMACNA Table 5-1 for your duct class and seal specification.
Industry Standards Referenced
Frequently Asked Questions
How do I convert m³/h back to CFM?
Divide by 1.69901. For quick estimates, multiply m³/h by 0.589 to get CFM. For exact conversion, use 1 m³/h = 0.5886 CFM.
Is this the same for standard and actual flow?
The conversion factor is a unit conversion, so it applies regardless of standard vs actual conditions. However, SCFM and ACFM differ as described in the SCFM to ACFM converter.
What about CFM to m³/s?
First convert CFM to m³/h, then divide by 3600. So 100 CFM = 169.9 m³/h = 0.0472 m³/s.
Does altitude affect the CFM to m³/h conversion?
No — this is a pure geometric conversion between units of volume. Altitude affects air density and therefore mass flow, but a cubic foot is always exactly 0.0283168 cubic meters regardless of elevation. If you need mass flow (lb/min or kg/s), apply density correction for altitude and temperature separately after converting the volumetric units.
How precise is the 1.69901 conversion factor?
The factor 1.69901 is based on the international foot definition (1 ft = 0.3048 m exactly), making it traceable to the SI meter. At the 6-significant-digit level, the full value is 1.6990108. The 1.69901 rounding introduces less than 0.00005% error — negligible compared to typical airflow measurement instrument accuracy of ±3–5% for pitot traverses and ±2% for calibrated orifice plates. For engineering calculations, 1.699 is sufficient; use the full value for fan certification testing per AMCA 210.
Reviewed for accuracy
Reviewed against SMACNA and ASHRAE 62.1 standards · Last reviewed: June 7, 2026
All calculations are for reference only. Always verify with manufacturer data and a qualified engineer for critical applications. Learn about our editorial process.