The ductulator, in your pocket
Enter CFM and get a real stocked size, velocity, and which constraint is governing. Round or rectangular; galvanized, flex, or lined — assumptions stated on the card.
220 CFM → 8″ round
630 fpmWithin
For service & install techs
Size a duct, read total static pressure, or check an existing run — right on the truck. Free field tools, offline, no account, nothing leaves your phone. Full Manual D system design is on the way.
Free · offline · no account
Built for the call, not the office. Quick Size starts from air you need; Diagnose starts from metal that exists. Punch in what you can measure and get a clean verdict that states what it assumed — legible enough to screenshot or share.
Enter CFM and get a real stocked size, velocity, and which constraint is governing. Round or rectangular; galvanized, flex, or lined — assumptions stated on the card.
Supply + return static against your equipment's rated max — total, verdict, and which side carries more of the load. Defaults to 0.50″ PSC until you set yours.
Existing size, airflow, and role → the friction rate it's running plus velocity against the limit. Verdict: undersized, adequate, or oversized.
The full deliverable