Duct Calculator Pro vs Pipe Sizer

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

PipeSizer helps you quickly choose the right pipe diameter for water systems — for both pressure and gravity flow. PRESSURE PIPE SIZING • Size pipes from a target flow rate. • Set your maximum friction rate and velocity limits. • Calculations based on the Hazen-Williams equation. GRAVITY PIPE SIZING • Size pipes from a target flow rate. • Evaluate flow capacity and velocity under gravity conditions. • Calculations based on the Manning equation. KEY FEATURES • Automatic recommended pipe size based on your limits. • Multiple pipe materials with built-in coefficients (more added over time). • Works in both SI and Imperial (I-P) units. • Designed for engineers, plumbers, and irrigation/drainage design workflows. Feedback is welcome — it directly shapes upcoming updates.