Free Engineering Calculators

Calculate sewage treatment plant capacity from population size using CPHEEO norms (135 lpcd). Get daily flow in KLD/MLD and peak flow factor.

Size an effluent treatment plant for industrial wastewater. Get aeration tank volume, hydraulic retention time, and sludge generation estimate.

Calculate the BOD/COD ratio and instantly assess wastewater biodegradability to determine the appropriate biological treatment process.

Estimate daily wastewater generation from residential, commercial, or industrial facilities using India-specific CPHEEO and BIS norms.

Size an MBBR reactor for BOD removal. Calculate required media surface area, fill percentage, and reactor volume based on loading rates.

Design an activated sludge aeration tank. Calculate tank volume, HRT, oxygen requirements, and blower capacity for your STP or ETP.

Calculate daily consumption of coagulants (alum, PAC), disinfectants (chlorine, hypochlorite), or pH adjustment chemicals for your plant.

Calculate permeate flow, reject flow, and concentration factor for reverse osmosis systems. Essential for ZLD system design.

Calculate hydraulic retention time (HRT) and sludge retention time (SRT) — fundamental parameters for biological treatment process design.

Calculate flow velocity, head loss, and Reynolds number for water and wastewater pipelines using the Darcy-Weisbach equation.

Calculate media block arrangement in circular SMAR tanks. Get blocks per layer, layer count, stack height, and total tank height with interactive plan and elevation views.