About this app
Duct Calculator is a simple, fast, and accurate tool designed for HVAC engineers, designers, technicians, and students. This app helps you calculate duct size, airflow velocity (FPM), and airflow rate (CFM) for both rectangular and round ducts with ease. Whether you are working on Heating, Ventilation, or Air Conditioning projects, this app provides quick calculations without requiring internet access. Key Features • No Internet Required – Works completely offline. • No Irritating Ads – Clean and smooth user experience. • Fast & Accurate Calculations – Built for HVAC professionals. • User-Friendly Interface – Simple layout for quick results. Available Calculators Duct Size Calculator Enter airflow rate (CFM) and airflow velocity (FPM) to get recommended rectangular and round duct sizes in inches. CFM Calculator Enter duct dimensions (length, width, or diameter in inches) and airflow velocity (FPM) to calculate airflow rate (CFM). FPM Calculator Enter duct size and airflow rate (CFM) to calculate airflow velocity (FPM). Who Should Use This App? Perfect for: • HVAC Engineers • Designers & Fabricators • Site Technicians • Students learning HVAC fundamentals
Latest release
What’s New
Upgraded to Higher SDK Levels. Changes in App Theme. Changes in App Layouts. Light and Dark Theme Supported. Fix Minor Bugs.
Audience growth
Ratings growth
Baseline captured. Growth appears after the crawler observes a changed rating count.
Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.
Price tracking
Price intelligence
First snapshot captured. The trend line starts after the next crawler price observation.
- First observed Aug 16, 2026 · 6:35 AM $3.99