Free Engineering Calculators

Estimate ETP plant CAPEX and OPEX for your industry. Get indicative cost ranges (₹ Lakhs to Crores) for food, pharma, dairy, and textile effluent treatment plants.

Calculate zero liquid discharge system cost, annual water savings, and energy requirements. See if ZLD makes financial sense for your plant.

Build the financial case for your ETP investment. Calculate annual savings, payback period, 5-year NPV, and risk-adjusted ROI.

Estimate sewage treatment plant cost for apartments, hospitals, and commercial buildings. Get CAPEX, monthly OPEX, and technology recommendation.

Calculate sludge volume, dry solids mass, and disposal cost from your ETP. Model dewatering options and estimate annual sludge management expenditure.

Estimate electricity consumption and energy cost for your effluent treatment plant. Identify high-energy unit operations and model energy-saving scenarios.

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.

Industry-specific ETP sizing for dairy, pharma, brewery, and textile plants. Get flow rate, BOD/COD load, and treatment system recommendations by sector.

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

Design a sequencing batch reactor for biological treatment. Calculate cycle time, tank volume, decant volume, and blower requirements.

Size a membrane bioreactor system. Get permeate flux, membrane area, tank volume, and aeration requirements for your MBR plant design.

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

Size a dissolved air flotation system for food & beverage wastewater. Get tank dimensions, sludge mass balance, material selection, and bill of quantities.

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

Size secondary settling tanks using surface overflow rate (SOR) and solids flux methods. Get clarifier diameter, SWD, HRT, weir overflow rate, and RAS flow.

Size EQ tanks using flow retention time and peak-shaving methods. Get working volume, tank L×W×D, HRT at average and peak flow, and mixing power.

Size upflow anaerobic sludge blanket reactors using OLR and HRT methods. Calculate reactor volume, upflow velocity, biogas yield, and electricity equivalent.

Calculate hydraulic power, motor kW, BHP, and annual energy cost for water and wastewater pumps. Includes IS standard motor sizing and wire-to-water efficiency.

Estimate daily VSS and TSS sludge generation from biological treatment using M&E observed yield equations. Get WAS volume and dewatered cake quantity.

Size filter press systems for ETP sludge dewatering — estimate plate count, filtration area, cake volume, and press footprint from feed sludge volume and solids.

Calculate UF membrane area, number of modules, skids, and corrected flux for ultrafiltration systems. Includes temperature correction factor per Metcalf & Eddy.

Calculate activated sludge aeration tank volume, MLSS, F:M ratio, oxygen demand, and WAS rate using Metcalf & Eddy kinetics. Essential for ETP/STP biological design.

Size combined nitrogen removal reactors — calculate nitrification zone volume, denitrification zone volume, SRT safety factor, and O₂ demand per Metcalf & Eddy.

Calculate primary sedimentation tank surface area, diameter, detention time, SOR, weir loading check, and primary sludge production per Metcalf & Eddy Chapter 6.

Size trickling filter media volume and diameter using the Germain equation. Supports plastic and rock media with temperature correction and recirculation.

Design horizontal flow grit channels using Stokes' law settling velocity. Calculate chamber length, depth, detention time, Froude number, and daily grit production.

Convert AOR to SOTR accounting for temperature, altitude, alpha/beta factors, and design DO. Size fine bubble diffusers, blowers, and surface aerators for aeration tanks.

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

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

Estimate caustic soda (NaOH) required to neutralise acidic wastewater. Get dosing rate, solution consumption, and batch preparation schedule.

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

Calculate alum, PAC, and ferric chloride daily consumption, dosing pump rate, sludge produced, and monthly chemical cost for your ETP coagulation stage.

Calculate NaOCl, Ca(OCl)₂, and Cl₂ gas consumption, dosing pump rate, contact tank volume, and monthly cost for STP/ETP disinfection.

Check if your wastewater has sufficient nitrogen and phosphorus for biological treatment. Calculate C:N:P ratio, nutrient deficiency, and urea/DAP supplement dose.

Calculate ozone dose for disinfection using the CT concept (Metcalf & Eddy). Get applied dose, daily O₃ consumption, generator rating, contact tank volume, and energy cost.

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

Calculate industrial wastewater reuse potential, annual freshwater savings, and cost benefit of treated water recycling for cooling, utilities, or process use.

Estimate biogas production from your UASB reactor or anaerobic digester. Calculate methane yield, energy potential, and equivalent CNG savings.

Size a biogas genset from your daily biogas flow. Calculate electrical kW output, heat recovery, annual electricity savings, CO₂ credits, and recommended engine size.

Compare Multiple Effect Evaporator and Mechanical Vapour Recompression systems on CAPEX, OPEX, energy consumption, and total cost of ownership for ZLD.

Model overall water recovery, energy consumption, and solid residue volume for a full Zero Liquid Discharge train — Primary RO, Brine RO, and MVR evaporator.

Calculate cooling tower blowdown rate, makeup water requirement, TDS in reject, and water savings at different cycles of concentration. Includes daily cost breakdown.

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

Check your treated effluent quality against CPCB general standards and state-specific discharge limits. Identify parameters that need further treatment.

Generate a SPCB consent-to-operate document checklist for your industry and state. Know exactly what to submit for CTO renewal or fresh application.

Calculate annual discharge load for Form V submission. Get monthly and annual pollutant mass load for BOD, COD, TSS, and other parameters.

Answer a few questions about your wastewater and get a recommended treatment technology — MBBR, MBR, SBR, or activated sludge — with rationale.

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