Duct Sizing Guide
A compact reference for choosing practical duct dimensions from airflow targets.
What matters most
Duct size depends on airflow, acceptable velocity, duct shape, and the design trade-off between noise and pressure drop.
Common mistakes
- Using supply-air velocity targets for branch ducts without adjustment.
- Ignoring fittings, transitions, and balancing losses.
- Choosing a size without checking noise limits.
When to use the calculator
Use it during preliminary duct routing, schematic design, or quick air distribution checks.