ENGINEERING CALCULATOR
Duct Air Velocity Calculator
Calculate air velocity from duct airflow and cross-sectional area.
Formula
Velocity (m/s) = airflow (m³/h) ÷ 3,600 ÷ duct area (m²).
How it works
Circular area = π × diameter² / 4. Rectangular area = width × height. Dimensions are in millimetres.
Limitations
Velocity is an average across the duct section. Actual flow profiles may be uneven.