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Find 100+ engineering calculators & tools for design, analysis, estimation, coursework and field work. Get clear results with formulas, units, and relevant engineering standards right beside the answer.
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Standards-based calculators for design checks, estimation and field decisions.
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Cable Size Calculator
Size conductors from load current using ampacity, derating factors and voltage-drop limits.
Open tool : Cable Size Calculator (opens in a new tab)Home Load Calculator
Add up household appliances, then size your inverter, battery bank and rooftop solar.
Open tool : Home Load Calculator (opens in a new tab)Transformer Calculator
Full-load current, short-circuit current, regulation and parallel-operation checks for any kVA.
Open tool : Transformer Calculator (opens in a new tab)Voltage Drop Calculator
Check DC, single-phase and three-phase drop against the usual 3% and 5% limits.
Open tool : Voltage Drop Calculator (opens in a new tab)Relay Coordination Tool
Plot IEC 60255 IDMT curves, verify CTI margins and grade overcurrent relays.
Open tool : Relay Coordination Tool (opens in a new tab)Electrical Symbol Finder
Search 60+ IEC circuit symbols by name or function and download each one as SVG.
Open tool : Electrical Symbol Finder (opens in a new tab)Transformer Sizing Calculator
Size the feeding transformer for motor and mixed loads with starting inrush and margins.
Open tool : Transformer Sizing Calculator (opens in a new tab)Ohm's Law Calculator
Solve voltage, current, resistance and power from any two known values instantly.
Open tool : Ohm's Law Calculator (opens in a new tab)Resistor / Capacitor / Inductor Color Code Calculator
Decode 4, 5 and 6-band resistors plus capacitor and inductor codes, with tolerance.
Open tool : Resistor / Capacitor / Inductor Color Code Calculator (opens in a new tab)Antenna Length Calculator
Size dipole, monopole, ground-plane and Yagi elements for any frequency and velocity factor.
Open tool : Antenna Length Calculator (opens in a new tab)Logic Gate Truth Table Generator
Build truth tables, simplify Boolean expressions and read Karnaugh maps for four variables.
Open tool : Logic Gate Truth Table Generator (opens in a new tab)Op-Amp Gain / Filter Designer
Design inverting, non-inverting and active filter stages with GBW and slew-rate checks.
Open tool : Op-Amp Gain / Filter Designer (opens in a new tab)PCB Trace Width Calculator
IPC-2221 trace width, temperature rise, resistance and via current capacity.
Open tool : PCB Trace Width Calculator (opens in a new tab)Subnet Calculator (CIDR)
Network address, broadcast, usable host range and mask conversion for any IPv4 CIDR block.
Open tool : Subnet Calculator (CIDR) (opens in a new tab)IP Address Class Finder
Identify class A to E, default mask, and whether an address is private or reserved.
Open tool : IP Address Class Finder (opens in a new tab)Number Base Converter
Convert between binary, octal, decimal, hexadecimal and any custom base instantly.
Open tool : Number Base Converter (opens in a new tab)Password Strength Checker
Estimate entropy and crack time, and see exactly which rules a password passes or fails.
Open tool : Password Strength Checker (opens in a new tab)Regex Tester & Builder
Test patterns against sample text offline, with match highlighting and a plain breakdown.
Open tool : Regex Tester & Builder (opens in a new tab)Big-O Complexity Estimator
Compare growth rates and estimate operation counts for common algorithms at any size.
Open tool : Big-O Complexity Estimator (opens in a new tab)Gear Ratio Calculator
Up to five gear stages with idlers, efficiency losses, output torque and an SVG diagram.
Open tool : Gear Ratio Calculator (opens in a new tab)Belt & Pulley Speed Calculator
Driven speed, belt length, wrap angle and slip check for open and crossed belt drives.
Open tool : Belt & Pulley Speed Calculator (opens in a new tab)Shaft Diameter Calculator
Size solid or hollow shafts under combined torque and bending, with angle-of-twist check.
Open tool : Shaft Diameter Calculator (opens in a new tab)Spring Design Calculator
Spring rate, Wahl-corrected stress, solid height and surge frequency for helical springs.
Open tool : Spring Design Calculator (opens in a new tab)Bearing Life (L10) Calculator
ISO 281 rating life in revolutions, hours and years from load rating and speed.
Open tool : Bearing Life (L10) Calculator (opens in a new tab)Concrete Mix Design Calculator
IS 10262 mix design for M20 to M40 with cement, sand and aggregate quantities.
Open tool : Concrete Mix Design Calculator (opens in a new tab)Bar Bending Schedule Generator
IS 2502 cutting lengths, bend deductions, hook allowances and total steel weight.
Open tool : Bar Bending Schedule Generator (opens in a new tab)Beam Deflection Calculator
Point load and UDL deflection with a span/250 check and live bending and shear diagrams.
Open tool : Beam Deflection Calculator (opens in a new tab)Column Design Load Calculator
IS 456 axial capacity, slenderness classification and reverse sizing for short columns.
Open tool : Column Design Load Calculator (opens in a new tab)Brick / Block Quantity Estimator
Bricks, cement bags, sand volume and total wall cost from your wall dimensions.
Open tool : Brick / Block Quantity Estimator (opens in a new tab)Chemical Dilution Calculator
Solve C1V1 = C2V2 for any unknown and get the exact stock and diluent volumes.
Open tool : Chemical Dilution Calculator (opens in a new tab)Molarity / Normality Calculator
Convert between mass, moles, molarity and normality for any solute and volume.
Open tool : Molarity / Normality Calculator (opens in a new tab)Reynolds Number Calculator
Classify pipe flow as laminar, transitional or turbulent from velocity and viscosity.
Open tool : Reynolds Number Calculator (opens in a new tab)pH Calculator (Acid-Base)
Find pH, pOH and hydrogen ion concentration for strong and weak acids and bases.
Open tool : pH Calculator (Acid-Base) (opens in a new tab)Distillation Column Basic Sizing
McCabe-Thiele lite: minimum reflux, theoretical stages and first-pass column height.
Open tool : Distillation Column Basic Sizing (opens in a new tab)Lift & Drag Coefficient Calculator
Derive Cl and Cd from lift, drag, wing area and dynamic pressure, then read L/D.
Open tool : Lift & Drag Coefficient Calculator (opens in a new tab)Rocket Equation (Tsiolkovsky) Calculator
Tsiolkovsky delta-v from mass ratio and specific impulse, with propellant breakdown.
Open tool : Rocket Equation (Tsiolkovsky) Calculator (opens in a new tab)Mach Number Calculator
Mach number and flow regime from true airspeed, altitude and local speed of sound.
Open tool : Mach Number Calculator (opens in a new tab)Wing Loading Calculator
Wing loading, stall speed and thrust-to-weight for fixed-wing aircraft and UAV designs.
Open tool : Wing Loading Calculator (opens in a new tab)Orbital Velocity Calculator
Circular orbital velocity, period and escape velocity for any altitude around any body.
Open tool : Orbital Velocity Calculator (opens in a new tab)EV Battery Range Estimator
Estimate real-world range from pack capacity, consumption, payload and driving style.
Open tool : EV Battery Range Estimator (opens in a new tab)Fuel Efficiency (Mileage) Calculator
Convert between kmpl, mpg and L/100 km, and work out trip fuel cost from distance.
Open tool : Fuel Efficiency (Mileage) Calculator (opens in a new tab)Engine Power / Torque Converter
Convert HP, kW, BHP and Nm at any engine speed, with a torque-power relationship view.
Open tool : Engine Power / Torque Converter (opens in a new tab)Braking Distance Calculator
Reaction plus braking distance from speed, friction, road grade and reaction time.
Open tool : Braking Distance Calculator (opens in a new tab)EV Charging Time Estimator
Charging duration from pack size, state of charge, charger power and efficiency.
Open tool : EV Charging Time Estimator (opens in a new tab)OEE Calculator
Overall equipment effectiveness from availability, performance and quality, with benchmarks.
Open tool : OEE Calculator (opens in a new tab)Economic Order Quantity (EOQ) Calculator
Optimal order size, reorder point and total inventory cost from demand and cost inputs.
Open tool : Economic Order Quantity (EOQ) Calculator (opens in a new tab)Line Balancing Efficiency Calculator
Cycle time, minimum stations, balance delay and line efficiency for assembly lines.
Open tool : Line Balancing Efficiency Calculator (opens in a new tab)Inventory Carrying Cost Estimator
Annual carrying cost as a percentage of inventory value, split by each cost driver.
Open tool : Inventory Carrying Cost Estimator (opens in a new tab)Machine Cycle Time Estimator
Cycle time, throughput per shift and takt comparison from setup, run and handling times.
Open tool : Machine Cycle Time Estimator (opens in a new tab)PID Controller Tuning Estimator
Ziegler-Nichols and Cohen-Coon gains from step response or ultimate gain and period.
Open tool : PID Controller Tuning Estimator (opens in a new tab)Sensor Range / Accuracy Converter (4-20 mA)
Convert between 4-20 mA, 0-10 V and engineering units, with the error band at any point.
Open tool : Sensor Range / Accuracy Converter (4-20 mA) (opens in a new tab)Control Valve Cv Sizing Calculator
Flow coefficient Cv and Kv for liquid service, with choked-flow and pressure-drop checks.
Open tool : Control Valve Cv Sizing Calculator (opens in a new tab)Instrument Air Consumption Estimator
Total plant instrument-air demand from valve and positioner counts and duty cycle.
Open tool : Instrument Air Consumption Estimator (opens in a new tab)Signal Loop Wiring Calculator
Loop resistance budget, maximum cable length and compliance voltage for a 4-20 mA loop.
Open tool : Signal Loop Wiring Calculator (opens in a new tab)Carbon Footprint Calculator
Annual CO2 footprint from electricity, fuel, travel and waste in one place.
Open tool : Carbon Footprint Calculator (opens in a new tab)Rainwater Harvesting Tank Size Calculator
Size a storage tank from roof catchment area, local rainfall and daily demand.
Open tool : Rainwater Harvesting Tank Size Calculator (opens in a new tab)Water Treatment Dosing Calculator
Coagulant, chlorine and lime dose plus daily chemical demand for a treatment plant.
Open tool : Water Treatment Dosing Calculator (opens in a new tab)BOD / COD Estimator
Estimate BOD, COD and their ratio to gauge how biodegradable a wastewater is.
Open tool : BOD / COD Estimator (opens in a new tab)Solid Waste Generation Estimator
Daily and annual municipal solid-waste load from population and per-capita rate.
Open tool : Solid Waste Generation Estimator (opens in a new tab)Blast Hole Pattern Calculator
Burden, spacing, powder factor and charge per hole for a surface blast pattern.
Open tool : Blast Hole Pattern Calculator (opens in a new tab)Drilling Mud Weight Calculator
Mud weight, hydrostatic pressure and equivalent circulating density for a well.
Open tool : Drilling Mud Weight Calculator (opens in a new tab)Ore Grade / Tonnage Estimator
Contained metal and recoverable tonnage from ore grade, volume and recovery rate.
Open tool : Ore Grade / Tonnage Estimator (opens in a new tab)Reservoir Volume Estimator (OOIP)
Original oil in place from area, net pay thickness, porosity and water saturation.
Open tool : Reservoir Volume Estimator (OOIP) (opens in a new tab)Wellhead Pressure Converter
Convert wellhead pressure across psi, bar, kPa and mud-weight gradient.
Open tool : Wellhead Pressure Converter (opens in a new tab)BMI + Medical Dosage Unit Converter
Body mass index, body surface area and weight-based dosage for clinical calculations.
Open tool : BMI + Medical Dosage Unit Converter (opens in a new tab)DNA / RNA Codon Translator
Translate DNA or RNA sequences into amino acids with reading-frame options.
Open tool : DNA / RNA Codon Translator (opens in a new tab)ECG Signal Sampling Rate Calculator
Nyquist-safe sampling rate, storage size and aliasing check for ECG and biosignals.
Open tool : ECG Signal Sampling Rate Calculator (opens in a new tab)Irrigation Water Requirement Calculator
Crop water requirement from evapotranspiration, crop coefficient, rainfall and efficiency.
Open tool : Irrigation Water Requirement Calculator (opens in a new tab)Crop Yield Estimator
Expected yield per hectare from plant density, grains per head and grain weight.
Open tool : Crop Yield Estimator (opens in a new tab)Tractor / Farm Machinery Power Calculator
Tractor drawbar power, PTO requirement and implement matching from draft and speed.
Open tool : Tractor / Farm Machinery Power Calculator (opens in a new tab)Solar / Wind Hybrid System Sizing Tool
Size a solar-plus-wind hybrid with battery backup from your daily load and site resource.
Open tool : Solar / Wind Hybrid System Sizing Tool (opens in a new tab)Carbon Credit Estimator for Renewable Projects
Estimate annual carbon credits and revenue from a solar, wind or biomass project's output.
Open tool : Carbon Credit Estimator for Renewable Projects (opens in a new tab)Ship Stability (Metacentric Height) Calculator
Metacentric height, righting lever and initial stability from KB, BM and KG values.
Open tool : Ship Stability (Metacentric Height) Calculator (opens in a new tab)Propeller Pitch Calculator
Theoretical speed, slip and pitch selection from engine RPM, gear ratio and diameter.
Open tool : Propeller Pitch Calculator (opens in a new tab)Scientific Calculator
Full scientific calculator with trig, logs, powers, memory and radian or degree modes.
Open tool : Scientific Calculator (opens in a new tab)Percentage Calculator
Percentage of a number, percentage change and reverse-percentage, all in one place.
Open tool : Percentage Calculator (opens in a new tab)Engineering Unit Calculator
Convert across length, mass, pressure, power, flow and dozens more unit families.
Open tool : Engineering Unit Calculator (opens in a new tab)Power Calculator
Raise numbers to any power, take roots and read scientific-notation results instantly.
Open tool : Power Calculator (opens in a new tab)Arc Flash Incident Energy Estimator
IEEE 1584 incident energy, arc-flash boundary and PPE category from bolted fault current.
Open tool : Arc Flash Incident Energy Estimator (opens in a new tab)Backup Generator Sizing Calculator
Size a standby generator from running and starting kVA, with step-load and derating checks.
Open tool : Backup Generator Sizing Calculator (opens in a new tab)Battery Pack Thermal Runaway Spacing Screening Tool
Screen cell and module spacing to slow thermal-runaway propagation in lithium battery packs.
Open tool : Battery Pack Thermal Runaway Spacing Screening Tool (opens in a new tab)Conduit Fill Calculator
NEC conduit fill percentage and the largest conduit trade size for your conductor mix.
Open tool : Conduit Fill Calculator (opens in a new tab)EV Home Charger Load Compatibility Checker
Check whether your panel can take a Level 2 charger using an NEC load calculation.
Open tool : EV Home Charger Load Compatibility Checker (opens in a new tab)Illuminance / Lux Level Calculator
Lumens, lux and fixture count for a room using the lumen method and target lux.
Open tool : Illuminance / Lux Level Calculator (opens in a new tab)Power Factor Correction Capacitor Sizing Calculator
kVAR capacitor size to lift power factor to target, with current and saving estimates.
Open tool : Power Factor Correction Capacitor Sizing Calculator (opens in a new tab)Residential Electrical Panel Upgrade Checker
Whether a 100 A to 200 A service upgrade is needed from an NEC dwelling load calc.
Open tool : Residential Electrical Panel Upgrade Checker (opens in a new tab)Short-Circuit Fault Current Calculator
Available fault current by the point-to-point method for breaker interrupting ratings.
Open tool : Short-Circuit Fault Current Calculator (opens in a new tab)Time-of-Use Electricity Cost & Peak Shaving Calculator
Compare time-of-use tariffs and estimate savings from shifting or shaving peak load.
Open tool : Time-of-Use Electricity Cost & Peak Shaving Calculator (opens in a new tab)V2G Revenue & Energy Flow Estimator
Vehicle-to-grid revenue and battery throughput from tariff spread and cycling limits.
Open tool : V2G Revenue & Energy Flow Estimator (opens in a new tab)3D Printing Cost & Material Estimator
Filament or resin usage, print time and total part cost for FDM and SLA 3D prints.
Open tool : 3D Printing Cost & Material Estimator (opens in a new tab)AI Data Center Liquid Cooling Load Calculator
Rack heat load, coolant flow and CDU sizing for direct-to-chip liquid-cooled AI racks.
Open tool : AI Data Center Liquid Cooling Load Calculator (opens in a new tab)Drone Flight Time & Payload Calculator
Hover and cruise flight time from battery, weight and payload for a multirotor drone.
Open tool : Drone Flight Time & Payload Calculator (opens in a new tab)Heat Pump Sizing & Manual J Estimator
Heating and cooling load with a Manual J lite estimate to size a home heat pump.
Open tool : Heat Pump Sizing & Manual J Estimator (opens in a new tab)Heat Pump Water Heater Payback & CO2 Calculator
Energy, running cost, payback and CO2 savings of a heat-pump water heater versus electric or gas.
Open tool : Heat Pump Water Heater Payback & CO2 Calculator (opens in a new tab)Projectile Motion & Free-Fall Calculator
Range, peak height, time of flight and impact velocity for projectile and free-fall motion.
Open tool : Projectile Motion & Free-Fall Calculator (opens in a new tab)Psychrometric Calculator
Humidity ratio, dew point, enthalpy and wet-bulb from dry-bulb temperature and humidity.
Open tool : Psychrometric Calculator (opens in a new tab)Refrigerant Charge & Line-Set Calculator
Refrigerant charge adjustment for line-set length and diameter on split AC and heat pumps.
Open tool : Refrigerant Charge & Line-Set Calculator (opens in a new tab)Insulation R-Value & U-Value Calculator
Assembly R-value, U-value and effective resistance for a multi-layer wall or roof build-up.
Open tool : Insulation R-Value & U-Value Calculator (opens in a new tab)Manning's Open Channel Flow Calculator
Flow rate, velocity and normal depth in open channels using the Manning equation.
Open tool : Manning's Open Channel Flow Calculator (opens in a new tab)Whole-Life Embodied Carbon Calculator
Embodied carbon of a building's materials across its life cycle, in kgCO2e.
Open tool : Whole-Life Embodied Carbon Calculator (opens in a new tab)Green Hydrogen Electrolyzer Sizing Calculator
Electrolyzer capacity, power and water demand for a target green-hydrogen output.
Open tool : Green Hydrogen Electrolyzer Sizing Calculator (opens in a new tab)Solar System Size & Payback Calculator
PV array size, annual generation, bill offset and payback from your roof and usage.
Open tool : Solar System Size & Payback Calculator (opens in a new tab)Air Quality Index (AQI) Calculator
Convert PM2.5, PM10, ozone and other pollutant levels into the AQI and its health band.
Open tool : Air Quality Index (AQI) Calculator (opens in a new tab)No tool matches that yet
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Results follow IS, IEC, NEC, IEEE, ISO, ASHRAE and IPC references where they apply.
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