EngineeringFormulaFlow Rate Conversion
Convert CFM to m³/h
1 CFM = 1.699 m³/h
HVAC equipment specced by US manufacturers is rated in CFM; specs from EU or ISO-standard manufacturers use m³/h. This conversion comes up whenever a duct, fan, or exhaust rating needs to be compared across both.
CFM means cubic feet per minute. Converting the volume unit first (1 ft³ = 0.0283168 m³) and then the time base (per minute to per hour, ×60) gives 1 CFM = 0.0283168 × 60 = 1.699 m³/h.
A typical residential bathroom exhaust fan is rated around 80-110 CFM (roughly 136-187 m³/h); a whole-house ventilation system might move 400-1,000+ CFM (680-1,700+ m³/h).
Practical next step
If the converted airflow is for a room or duct, use the CFM Calculator, Duct Size Calculator, or Air Changes per Hour Calculator next so the number becomes an actionable ventilation or duct-sizing check.
Reference Table
| cubic feet per minute (CFM) | cubic meters per hour (m³/h) |
|---|---|
| 1 | 1.699 |
| 5 | 8.495 |
| 10 | 16.99 |
| 25 | 42.475 |
| 50 | 84.95 |
| 100 | 169.9 |
Used In These Calculators
Frequently Asked Questions
Why isn't there a single universal airflow unit?
CFM and m³/h measure the same physical quantity - volumetric flow rate - just in different unit systems that took hold in different regions. There's no technical reason both persist; it's purely a legacy of US customary vs. metric adoption in HVAC manufacturing.
Is CFM measured per minute even though m³/h is per hour?
Yes - CFM is inherently a per-minute rate by definition, and this conversion changes both the volume unit and the time base at once (feet to meters, and minutes to hours). That's why the multiplier isn't just the simple ft³-to-m³ factor on its own; it also carries the ×60 for the time-base change.
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