HVAC Duct Sizing

Interactive Ductulator

Size ductwork instantly. Compare 4 simultaneous profiles, calculate CFM, velocity, and friction loss with visual scaled diagrams — all based on ASHRAE Fundamentals.

$2.99 One-time purchase

Coming Soon to Google Play Save 27% with MEP Toolkit

Interactive Ductulator showing four duct profiles side by side

Duct Sizing, Solved

Built for HVAC engineers, mechanical designers, and sheet metal detailers.

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4 Simultaneous Profiles

Compare 2 rectangular, 1 round, and 1 flat oval profile side by side. See all your options at once.

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Auto-Calculate Everything

Enter any two of CFM, velocity (FPM), or friction loss (in. wg/100ft) and the third calculates automatically.

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5 Duct Materials

Galvanized steel, stainless steel, aluminum, fiberglass board, and flex duct — each with accurate roughness factors.

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Visual Scaled Diagrams

See duct cross-sections drawn to scale with live dimension labels. Aspect ratio displayed for manufacturability checks.

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Snap to Standard Sizes

Toggle snap-to-standard to lock dimensions to standard manufactured sizes. No guesswork.

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Share Results

Share duct sizing results directly with your team from the app. ASHRAE Equal Friction Loss method documented.

Save 27% with MEP Toolkit

Get Interactive Ductulator plus Pipe Schematic Pro and Point Load Calculator for just $7.99 instead of $10.97.

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