Engineering calculators, formulas included.
Interactive calculators for common engineering calculations. These are separate from the deterministic unit conversion pages — calculators combine multiple inputs and may require user-supplied properties like density or efficiency.
Every calculator shows its formula, assumptions, limitations, and a worked example. Grouped by engineering area so you can find the right tool in one scan.
- Calculators
- 91
- Areas
- 15
Calculators by area
Fluid Mechanics
11 calculatorsHead, pressure, flow and dimensionless numbers for fluid systems.
Head ↔ Pressure Calculator
Convert between fluid head (height) and pressure using density and gravity.
Mass Flow ↔ Volumetric Flow Calculator
Convert between mass flow rate and volumetric flow rate using fluid density.
Reynolds Number Calculator
Calculate the Reynolds number for internal pipe flow and classify the flow regime as laminar, transitional, or turbulent.
Hydrostatic Pressure Calculator
Calculate the pressure at the base of a static liquid column from fluid density, height, and gravity, or solve for height or density.
Bernoulli Equation Calculator
Apply the Bernoulli equation for ideal incompressible flow between two points. Calculate P₂ from pressures, velocities, elevations, and optional user-supplied head loss.
Differential Pressure Calculator
Calculate differential pressure from two pressures, or from density and liquid height. Simple arithmetic and static head modes.
Orifice Flow Calculator
Calculate volumetric flow through an orifice plate from orifice diameter, discharge coefficient, differential pressure, and fluid density.
Friction Factor Calculator
Calculate the Darcy friction factor from Reynolds number and relative roughness using the laminar formula or Swamee-Jain explicit turbulent approximation.
Hazen-Williams Head Loss Calculator
Estimate friction head loss in water-service pipes using the empirical Hazen-Williams equation, with velocity, optional elevation head, total head, and the equivalent pressure drop for water. Preliminary water-service estimate only.
Liquid Valve Cv Calculator
Estimate liquid valve flow coefficient Cv from flow, pressure drop, and specific gravity — or solve for pressure drop or flow — with the Kv equivalent. Simple turbulent liquid sizing screen only, not a control-valve selection tool.
Manning Open-Channel Flow Calculator
Estimate normal open-channel flow in a simple rectangular channel using the Manning equation — flow area, wetted perimeter, hydraulic radius, flow rate, and velocity from width, depth, slope, and roughness. Preliminary estimate only.
Piping
7 calculatorsVelocity, flow rate, pressure drop and losses in pipe networks.
Pipe Velocity / Flow / Diameter Calculator
Calculate pipe velocity, volumetric flow, or internal diameter from the other two values.
Pipe Flow Rate Calculator
Calculate volumetric flow rate, velocity, or internal diameter for a circular pipe from the other two values using continuity.
Darcy-Weisbach Pressure Drop Calculator
Calculate pressure drop and head loss in a straight circular pipe from user-supplied Darcy friction factor, pipe geometry, fluid density, and velocity.
Minor Loss / K-Value Loss Calculator
Calculate head loss and pressure loss from a user-supplied loss coefficient (K-value) for a pipe fitting, valve, or other flow obstruction.
Equivalent Length Calculator
Convert a fitting loss coefficient (K-value) to an equivalent length of straight pipe, or calculate K from equivalent length and friction factor.
Pipe Head Loss Calculator
Combine major (friction) and minor (K-value) head losses into a total head loss and equivalent pressure drop for a pipe run.
Pipe Pressure Drop Calculator
Estimate the pressure drop and head loss in a straight circular pipe from flow rate, pipe size, and fluid properties — Darcy-Weisbach friction with an optional minor-loss (K) and elevation allowance. Friction factor is computed for you.
Process Design
19 calculatorsSizing, mixing, concentration and throughput for vessels and processes.
Residence Time Calculator
Calculate hydraulic residence time, vessel volume, or volumetric flow rate from the other two values.
Tank Volume Calculator
Calculate the internal volume of rectangular, vertical cylindrical, or horizontal cylindrical tanks from dimensions.
Tank Diameter & Height Calculator
Estimate cylindrical tank volume from diameter and straight-side height, or size the required diameter or height for a target working volume, with an optional fill fraction.
Dilution Calculator
Calculate dilution using C₁V₁ = C₂V₂. Solve for any one of concentration or volume when the other three are known.
Concentration Calculator
Calculate mass concentration, solute mass, mass fraction, and percent by mass from basic inputs.
Slurry Solids Calculator
Calculate percent solids, solids mass flow, slurry mass flow, or liquid mass flow for a slurry stream on a mass basis.
Slurry Density Calculator
Calculate slurry density and percent solids from liquid density, solids density, and the solids loading — entered as mass percent, volume percent, or g/L of slurry. Includes a target-density lab-prep mode that returns the mixture proportions for a desired slurry density.
Slurry Mass Balance Calculator
From slurry volumetric flow, slurry density, and percent solids by mass, calculate slurry/solids/liquid mass flows, component volumetric flows, and percent solids by volume.
Percent Solids Mass ↔ Volume Calculator
Convert between percent solids by mass (Cw) and percent solids by volume (Cv) using the liquid density and the solids density. Returns the slurry density, slurry SG, all four phase fractions, and the liquid:solids ratios.
Slurry Blending (Two-Stream) Calculator
Blend two slurry streams: from each stream’s volumetric flow, slurry density, and percent solids by mass, calculate the combined flow, slurry/solids/liquid mass flows, blended slurry density, and blended percent solids by mass (and by volume if densities are supplied).
Tank Turnover Calculator
Estimate tank turnover rate, turnover time, and total turnovers from flow rate, tank volume, and time period.
Horizontal Tank Partial Volume Calculator
Estimate the liquid volume in a horizontal cylindrical tank from inside diameter, straight length, and liquid depth, with fill fraction and ullage.
Cone-Bottom Tank Volume Calculator
Estimate the total and partial volume of a cylindrical vessel with a conical bottom — cylinder volume, cone volume, cone fraction, and volume at a fill level.
Rectangular Tank Volume Calculator
Estimate the total and working volume of a rectangular tank, basin, or sump from length, width, height, and liquid depth, with freeboard and ullage.
Tank Freeboard Calculator
Estimate freeboard height, working liquid depth, working volume, and ullage volume for a rectangular or vertical cylindrical tank — from either the liquid depth or the freeboard.
Surge Volume Calculator
Estimate the surge / buffer volume needed to absorb a net flow imbalance over a hold-up time, or the available surge time from a known volume — with an optional design allowance.
Batch Tank Sizing Calculator
Estimate the working liquid volume and geometric tank volume for a batch tank from batch size, number of batches held, working fill fraction, heel/dead volume, and an optional contingency allowance.
RTD Tracer Test Calculator
Estimate the mean residence time and a simple residence-time-distribution (RTD) summary — area under the response curve, mean residence time, variance, standard deviation, and dimensionless variance — from a tracer test concentration/response profile using trapezoidal integration. Preliminary summary only.
Pulp / Slurry Volumetric Flow Calculator
Convert a dry solids tonnage, percent solids by mass, solids SG, and liquid density into a slurry volumetric flow (m³/h), with the slurry mass flow, liquid flows, phase volume flows, and slurry density. A preliminary two-phase mass/volume balance, not a rheology or slurry-pipeline design tool.
Comminution
4 calculatorsGrinding circuit load, screen efficiency, reduction ratio and work index.
Circulating Load Calculator
Estimate the circulating load ratio, circulating load percentage, and total mill feed of a closed grinding circuit from the fresh feed and circulating (recycle) return tonnages. A preliminary operating mass-flow check, not a cyclone, mill-power, or grinding-efficiency model.
Screen Efficiency Calculator
Estimate screen undersize-recovery efficiency and the undersize loss to oversize from the undersize material in the feed and the undersize reporting to the undersize product. A preliminary undersize-recovery calculation, not a screen sizing or selection method.
Reduction Ratio Calculator
Calculate the comminution reduction ratio (F80 / P80) and percent size reduction from a feed size and product size in the same unit. A dimensionless same-unit size ratio, not a particle-size conversion, crusher selection, or mill design tool.
Bond Work Index Calculator
Calculate Bond Third-Theory specific grinding energy from a supplied work index, F80, and P80, or the reverse operating work index from measured specific energy. A preliminary formula calculator, not a grindability test, ore-Wi predictor, or mill-sizing tool.
Flotation
1 calculatorCell capacity and residence time for froth flotation circuits.
Hydrometallurgy
17 calculatorsLeaching, thickening, filtration and slurry conditioning for wet processing.
Leach Tank Residence Time Calculator
Estimate the hydraulic residence time across a leach tank or tank train from slurry flow, number of tanks, and working volume per tank, with optional online factor and design margin.
CIL Tank Residence Time Calculator
Estimate the hydraulic residence time in a carbon-in-leach (CIL) tank train from slurry flow, number of tanks, and working volume, with an optional carbon-inventory estimate.
CCD Wash Water Calculator
Estimate the wash-water flow required in a counter-current decantation (CCD) circuit from the dry solids rate, thickener underflow solids concentration, and a target wash ratio.
Thickener Underflow Density Calculator
Estimate thickener underflow slurry density and component flows from the dry solids rate, target underflow wt% solids, solids density, and liquid density.
Leach Reagent Consumption Calculator
Estimate reagent consumption rate and daily consumption from dry solids throughput and reagent dosage, with an optional daily reagent cost.
Cyanide Solution Preparation Calculator
Estimate the sodium cyanide (NaCN) mass needed to prepare a target solution concentration, or the stock-solution and dilution-water volumes for a target strength — a preliminary mass balance only.
Lime Slurry Preparation Calculator
Estimate the lime mass and water required to prepare a milk-of-lime slurry at a target solids concentration by mass — a preliminary make-up mass balance only.
Flocculant Make-down Calculator
Estimate dry polymer mass, make-down solution flow, and dosing rate for a target flocculant solution concentration and plant dose — a preliminary make-down and dosing estimate only.
Thickener Feed Dilution Calculator
Estimate the dilution water required to drop a thickener feed slurry from an initial solids concentration to a lower target feed solids concentration — a preliminary dilution mass balance only.
Thickener Water Recovery Calculator
Estimate the process water recovered to a thickener overflow from the dry solids rate, feed solids concentration, and underflow solids concentration — a preliminary water-balance estimate only.
Thickener Solids Loading Rate Calculator
Estimate the operating unit-area solids loading rate and hydraulic rise/overflow rate for a thickener of known diameter — an operating check only, not a thickener sizing tool.
Slurry Dilution Water Calculator
Estimate the dilution water required to dilute a slurry from an initial wt% solids to a lower target wt% solids on a dry-solids basis — a preliminary slurry dilution mass balance only.
Filtration Mass Balance Calculator
Run the two-phase mass/water balance across a filter: cake solids, cake water, total wet cake, water removed to filtrate, solids recovery to cake, and solids lost to filtrate, from the feed dry-solids rate, feed % solids, and cake moisture (with an optional filtrate solids loss). A preliminary balance on measured data, not a filtration performance predictor or simulator.
Filter Cake Moisture & Solids Calculator
Convert a wet and dry filter-cake mass into the cake moisture on both bases — wet-basis moisture, dry-basis moisture, cake % solids, and the water-to-solids ratio — with the water held in the cake. Clearly separates wet basis from dry basis. A mass split of a measured cake, not a moisture predictor.
Filter Area & Capacity Calculator
An OPERATING CHECK that returns the required filter area and the dry-cake production rate from a dry-solids throughput and a filtration rate YOU supply (from a leaf test, testwork, or the literature), with an optional on-stream factor. It is NOT equipment sizing, equipment selection, or vacuum/pressure-filter design.
Kiln Residence Time Calculator
Estimate rotary-kiln solids residence time from length, internal diameter, rotation speed and slope using the Sullivan, Maier & Ralston (1927) relation t = 0.19·L/(N·D·s), with three-mode slope entry (m/m, %, degrees).
Leach Tank Sizing Calculator
Size leach/agitation tanks for a stated residence time from slurry flow (direct Q or a solids basis), residence time, tanks in series and live-volume fraction, with per-tank volume and optional D and H.
Metallurgical Accounting
3 calculatorsMass balance and recovery from two- and three-product formulas.
Two Product Formula Calculator
Calculate metallurgical recovery, mass yield (mass pull), ratio of concentration, and enrichment ratio from measured feed, concentrate, and tailings assays — a two-product mass-balance accounting tool, not a recovery prediction.
Ratio of Concentration Calculator
Calculate the ratio of concentration — the tonnes of feed treated per tonne of concentrate produced — from measured feed, concentrate, and tailings assays, with the reciprocal mass yield, recovery, and enrichment ratio for context. An assay mass-balance relationship, not a performance prediction.
Three Product Formula Calculator
Perform a simplified three-product metallurgical balance: solve the two-metal, four-stream assay balance for each concentrate’s mass fraction of feed and the recovery of each metal to each concentrate. A mass-balance accounting tool, not a separation model.
Instrumentation
9 calculatorsSignal scaling, RTD measurement and sensor range calculations.
4–20 mA Scaling Calculator
Scale a 4–20 mA analog signal to a process variable, or reverse-calculate the mA value for a given process value.
mA to Process Value Calculator
Convert a 4–20 mA instrument signal into the corresponding process value for a linear instrument range, using the lower and upper range values.
Process Value to mA Calculator
Convert a process value into the expected 4–20 mA signal for a linear instrument range, using the lower and upper range values.
Instrument Range / Span Calculator
Calculate instrument span, percent of range, and the process-value/percent-span relationship from the lower and upper range values.
RTD Temperature Calculator
Estimate temperature from RTD resistance using the simple linear approximation for Pt100 or Pt1000 sensors.
Sensor Percent Span / Range Calculator
Calculate percent of span from a process value and instrument range, or reverse-calculate the process value from percent span.
Square Root Extraction Calculator
Convert between differential-pressure percent and flow percent for square-root DP flow measurement, with an optional low-flow cutoff.
DP Flow Signal Calculator
Estimate the 4–20 mA signal from flow percent for a square-root extracted DP flow transmitter, or recover flow percent from the mA signal.
Signal Error Percent Calculator
Calculate instrument signal error as a process-unit error, a percent of span, and an equivalent mA error for a linear instrument range.
Electrical
3 calculatorsResistance, power and voltage drop in electrical circuits.
Ohm's Law Calculator
Calculate voltage, current, or resistance using Ohm's law (V = IR). DC / resistive circuit basis.
Electrical Power Calculator
Calculate DC/resistive electrical power using P = VI, P = I²R, or P = V²/R.
Voltage Drop Calculator
Calculate resistive voltage drop, percent drop, and load voltage for a simple DC circuit or cable run.
Pumps & Rotating Equipment
5 calculatorsHydraulic power and affinity law scaling for pumps.
Pump Hydraulic Power Calculator
Calculate hydraulic power and shaft power from flow, head, density, gravity, and pump efficiency.
Pump Affinity Laws Calculator
Estimate new flow, head, and power when pump speed changes using the affinity laws (speed-change scaling).
NPSH Available Calculator
Estimate net positive suction head available (NPSHa) for preliminary suction-side pump checks, using head terms or absolute-pressure terms.
Total Dynamic Head Calculator
Estimate total dynamic head (TDH) from static elevation, suction and discharge pressure (or head), friction and minor losses, and an optional velocity-head change — using head terms or pressure terms, with a design allowance.
Pump Specific Speed Calculator
Calculate pump specific speed (metric Ns = n·√Q / H^¾) for preliminary pump-type context and sanity checks. Convention-sensitive — best evaluated near the best-efficiency point.
Heat Transfer
5 calculatorsSensible heat duty and thermal design calculations.
Heat Duty Calculator
Calculate sensible heat duty from mass flow rate, specific heat capacity, and temperature change. Continuous and batch modes.
LMTD Calculator
Calculate the log mean temperature difference (LMTD) for counter-current and co-current heat exchangers, with optional LMTD correction factor F for multi-pass configurations.
Fouling Factor Selector
Estimate fouling resistance and fouled overall heat-transfer coefficient for preliminary heat exchanger sizing.
Heat Exchanger Area Calculator
Estimate preliminary heat-transfer area from duty, U-value, LMTD, correction factor, and design margin.
Air-Cooled Heat Exchanger Sizing Calculator
Estimate preliminary air-cooled heat exchanger area, air flow, bay count, face velocity, and fan power for early-stage process checks.
Heat-transfer fluids
1 calculatorFreeze-protection and concentration selection for thermal fluids.
Refrigeration
2 calculatorsSuperheat and subcooling for refrigeration circuits.
Superheat Calculator
Calculate refrigerant superheat from gauge pressure (psig) and suction-line temperature (°F) for nine refrigerants, against the dew line for zeotropic blends.
Subcooling Calculator
Calculate refrigerant subcooling from gauge pressure (psig) and liquid-line temperature (°F) for nine refrigerants, against the bubble line for zeotropic blends.
Psychrometrics
3 calculatorsWet-bulb, dew point, humidity ratio and enthalpy for moist air.
Wet-Bulb Temperature Calculator
Calculate the wet-bulb temperature of moist air from dry-bulb temperature, relative humidity and pressure, with the full psychrometric property set.
Dew Point Calculator
Calculate the dew point of moist air from dry-bulb temperature, relative humidity and pressure, with the full psychrometric property set.
Humidity Ratio & Enthalpy Calculator
Calculate the humidity ratio (g/kg dry air) and specific enthalpy (kJ/kg dry air) of moist air from dry-bulb temperature, relative humidity and pressure, with the full psychrometric property set.
Mechanical
1 calculatorThermal expansion and dimensional change calculations.
These calculators cover instrumentation scaling, fluid head/pressure, mass/volumetric flow, pipe velocity, pump hydraulic power, heat duty, residence time, tank volume, thermal expansion, Reynolds number, Ohm's law, electrical power, voltage drop, RTD temperature, sensor percent span, dilution, concentration, slurry solids, tank turnover, pump affinity laws, hydrostatic pressure, Bernoulli equation, differential pressure, orifice flow, pipe flow rate, Darcy-Weisbach pressure drop, friction factor, minor loss, equivalent length, and pipe head loss. Additional calculators are planned for future packages.