The Duct Calculator App for iPhone/iPad is a specialized utility designed to aid HVAC engineers, designers, and contractors in the precise sizing of ductwork. This app modernizes the traditional duct sizing wheel, allowing users to quickly and accurately calculate the dimensions and performance of both round and rectangular ducts. With features such as adjustable airflow, diameter, width, and height sliders, users can either use intuitive sliders for quick adjustments or input exact numbers for maximum precision. The app ensures live updates of calculated values, reflecting any changes made in real-time.

The Duct Calculator also supports both IP and SI units and offers a variety of duct roughness categories. Users can lock specific dimensions to easily conduct 'what-if' scenarios, making it a versatile tool for HVAC design. The application outputs essential data such as velocity for both duct types and pressure drop per length, making it an invaluable resource for professionals in the field.