Fluid Mechanics Toolbox

Fluid Mechanics Toolbox is an offline engineering calculator for fluid mechanics, hydraulics, pipe flow, pumps, open channels, weirs, and unit conversion. Designed for engineers, students, designers, and field technicians, the app helps you perform common fluid and hydraulic screening calculations quickly without spreadsheets, accounts, ads, subscriptions, or internet access. Key features: • Pipe flow and pressure drop calculations • Darcy-Weisbach, Hazen-Williams, Manning and Bernoulli tools • Reynolds number, Froude number and other dimensionless numbers • Pump power, efficiency and NPSH calculations • Open channel, weir, orifice and Venturi calculations • SI and USCS unit systems • Offline unit converter • Built-in engineering reference tables • Local project workspace and favorites • Copy calculation results • Light mode, dark mode and system appearance • English and Simplified Chinese interface The app is built for one-time paid download use. No subscription, no ads, no login and no server connection are required. All calculations run offline on device. Disclaimer: This app is intended for learning, estimation, preliminary engineering screening and technical reference only. Results are based on user inputs and built-in formulas. Users are responsible for verifying results against applicable standards, project requirements, vendor data and professional engineering judgment before use in real projects.