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.

$1.99 One-time purchase

Save with MEP Toolkit

In final testing on Google Play. Public release expected in November.

Interactive Ductulator showing four duct profiles side by side

Duct Sizing, Solved

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

📊

4 Simultaneous Profiles

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

🔄

Auto-Calculate Everything

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

🏗️

5 Duct Materials

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

📐

Visual Scaled Diagrams

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

📏

Snap to Standard Sizes

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

📤

Share Results

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

Save with MEP Toolkit

Get Interactive Ductulator plus Pipe Schematic Pro and Point Load Calculator for $7.99 in the MEP Toolkit (a $8.97 value).

View MEP Toolkit