HVAC Duct Sizer Pro

Size a duct in seconds — on site, with no signal needed.

HVAC Duct Sizer Pro is a digital ductulator for mechanical engineers, designers and field technicians. Enter an airflow and a design criterion, and the duct size appears instantly, computed from ASHRAE Fundamentals duct-design methods.

SIZE MODE
• Enter airflow plus either a friction rate or a target velocity
• Exact round diameter, plus the nearest standard size (EN 1506 and imperial)
• Rectangular equivalent — give one side, get the other (Huebscher)
• Actual velocity, friction rate, velocity pressure and Reynolds number

ANALYZE MODE
• Enter airflow and an existing duct — round diameter or rectangular a×b
• Instantly see velocity, friction rate, velocity pressure and Reynolds number
• Check an existing run against design limits before you order material

REAL ENGINEERING, NOT A LOOKUP TABLE
• Colebrook–White friction factor, solved iteratively — not a chart approximation
• Duct material roughness: smooth, galvanized steel, lined, flex, rough
• Standard air, or your own custom density
• Hints for typical design ranges, and warnings for high aspect ratio or laminar flow

UNITS THAT FIT YOUR OFFICE
• SI and IP throughout
• Airflow in L/s, m³/h or CFM, chosen independently

WORKS ANYWHERE
• 100% offline — no account, no sign-up, no internet connection
• No ads, no subscription, no tracking, no data collection
• One single purchase, yours for good

Available in English, Japanese, Simplified Chinese, Korean, French, German, Spanish and Vietnamese.

From the developer of AirCalc Pro.