Air Duct Calculator

Last updated: 2026-08-24

Air Duct Calculator — Air duct sizing based on flow rate and velocity.
Inputs
Result
Enter values and press Calculate

How to use it

  1. Convert flow rate a m³/s: 500 m³/h ÷ 3600 = 0.139 m³/s
  2. Calculate cross-section: 0.139 m³/s ÷ 4 m/s = 0.0347 m²
  3. Calculate diameter: 2 × √(0.0347 ÷ Ï€) = 0.210m = 210mm
  4. Diámetro comercial: 200mm or 250mm according to disponibilidad

Common mistakes

  • ⚠️ Use speed muy alta (ruido excesivo)
  • ⚠️ Use speed muy baja (conductos muy grandes, costo greater)
  • ⚠️ Not Consider pérdidas per codos and derivaciones

Worked example

Calculate air duct cross-section for 0.5 m3/s flow at 5 m/s velocity.

To {caudal_m3h} m³/h a {velocidad_ms} m/s needs conducto of {diametro_mm}mm of diameter ({area_cm2} cm² of cross-section).

Input guide

FieldTypical range
velocidad_msRecommended velocity: main ducts 5-8 m/s, branches 3-5 m/s, grilles 1-2.5 m/s
caudal_m3hAirflow to transport. Residential: 150-500 m³/h, Office: 500-2000 m³/h, Commercial: 2000-10000 m³/h