Ductulator - Duct Sizing

Size HVAC ducts instantly using airflow, friction or velocity.
Get accurate duct dimensions in seconds — no charts required.

• Get a range of suitable duct sizes based on friction rate or velocity.
• Get multiple valid duct dimensions instantly.
• Tap on Friction Rate or Velocity to toggle between calculation methods.
• IP and SI units.
• Detailed sizing mode to adjust the duct dimensions and air flow rates.
• Supports rectangular, circular and flexible ducts.
• Automatic friction and velocity updates.

Calculations are based on standard air 0.075 lb/ft3 (1.2 kg/m3) in clean galvanized steel or non-metallic flexible ducts.

Any feedback is welcome, and will be the basis for future updates.