FREE ENGINEERING CALCULATORS

Chemical Dose & Feed Rate

Convert a treatment dose into active chemical mass, solution feed and storage use.

Chlorine CT & Contact Tank

Calculate nominal detention time, effective contact time and achieved CT.

Darcy Friction Factor

Calculate Darcy and Fanning friction factors from Reynolds number and roughness.

Cost estimation

Equipment Cost Scaling Calculator

Scale equipment cost to a new size, adjust its price date, and compare exponent assumptions.

Filter Loading & Backwash

Calculate operating filtration rate, required area and backwash water use.

Gas Control Valve Sizing Calculator

Calculate required Cv and Kv or gas capacity, including expansion and choked flow.

Gas Flow Calculator

Convert actual, standard or normal gas volume and mass flow at your operating conditions.

Heat Duty Calculator

Calculate heating or cooling duty including sensible heat, reaction heat, phase change, and environmental losses.

Heat Exchanger Calculator

Toggle known values to solve heat duty, outlet temperatures, flow rates, and exchanger conductance.

K Factor ↔ Equivalent Length

Convert a minor-loss coefficient to equivalent straight-pipe length, or back to K.

Cost estimation

Lang Factor Calculator

Estimate preliminary total plant cost from major equipment costs using a selectable Lang factor.

Lime-Soda Softening

Estimate stoichiometric lime and soda ash demand from hardness, alkalinity and free CO₂.

Liquid Orifice Flow

Estimate incompressible liquid flow or differential pressure across an orifice plate from a supplied discharge coefficient.

Process engineering

Material Balance Calculator

Calculate mass or molar balances across multiple streams, solve one unknown stream, and check component balances.

Minimum Disinfectant Residual

Estimate chlorine decay, required initial residual and dose to meet your endpoint target.

Multi-Layer Heat Transfer

Build a series stack of solid layers, convection films, and contact resistances; solve heat flow, temperatures, conductivity, thickness, or h.

Multi-Section Pipe System

Add pipes of different sizes, fittings, equipment losses and elevation changes. See total pressure requirement and a section breakdown.

Pumps

NPSH Available

Calculate NPSH available from absolute pressure, vapor pressure, elevation, and suction losses.

Pipe Friction Loss & Pressure Drop

Calculate pipe friction loss, pressure drop, and head loss for water and other liquids, including fittings.

Pipe Insulation Calculator

Estimate pipe heat loss or gain, insulation surface temperature, and savings at different thicknesses.

Networks

Pipe Network Solver

Solve looped liquid networks with pumps, tanks, valves, and time-varying demands using EPANET.

Pipe Sizing Calculator

Find the required inside diameter and compare standard pipe sizes for your flow and velocity limit.

Pipe Velocity

Calculate average velocity from volumetric flow rate and inside diameter.

Mechanical design

Pipe Wall Thickness Calculator

Estimate straight-pipe pressure thickness and nominal wall, or the pressure supported by a selected wall.

Pitot Tube Calculator

Calculate local velocity or differential pressure, with an optional duct-flow estimate.

Pumps

Pump Power

Calculate hydraulic and shaft power from flow, head or pressure rise, density, and efficiency.

Reynolds Number

Calculate Reynolds number from dynamic or kinematic viscosity and identify the flow regime.

RO Recovery & Concentrate

Balance feed, permeate and concentrate flows and dissolved-solids mass.

Mechanical design

Tank Volume Calculator

Calculate total capacity, liquid volume, and remaining space using an illustrated tank selector.

Valve Cv for Liquids

Solve liquid valve Cv, flow rate, or pressure drop using the basic incompressible sizing relation.

Venturi Flow Calculator

Solve liquid flow, throat differential pressure, or Venturi throat diameter.