Duct / cross-section calculator

Calculate the required cross-section and diameter from air flow and velocity.

Diameter (mm)
243
Cross-section (cm²)
463
01

A = V̇ / v

The cross-section is air flow divided by flow velocity.

02

To diameter

From the area, the round diameter follows via d = √(4·A/π).

03

Pick a velocity

Typical duct velocities are 2–5 m/s — higher gets noisy and pressure-heavy.

Rough calculation, no warranty; pressure loss and duct shape are not considered.

From measurement to finished quote

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