Engineering Calculators Comparison
All 67 Engineering calculators in one comparison table, with the formula and a worked example for each.
What you can work out with these calculators
Engineering calculators cover the repetitive checks that appear in electrical, mechanical and civil work: Ohm's law and power, conductor sizing, beam loading, torque and material estimates. Inputs and outputs keep their units, and where a published table or code reference applies it is named.
- Solve voltage, current, resistance and power from any two known values.
- Size a conductor from current, run length and acceptable voltage drop.
- Estimate beam load, reaction and deflection for common support arrangements.
- Convert between torque units and relate torque, speed and power.
Compare calculators by what you enter
All 67 calculators here, one row each: what each tool works out and the fields it asks for before it does. Open any row to use the calculator itself.
| Calculator | What it works out | What you enter |
|---|---|---|
| Voltage Drop Calculator | Calculate voltage drop in cable | Current (A) · Cable Length (m) · Resistance (Ω/km) |
| Power Factor Calculator | Calculate power factor | Real Power (W) · Apparent Power (VA) |
| Gear Ratio Calculator | Calculate gear ratio | Driver Teeth · Driven Teeth |
| Torque Calculator | Calculate torque with force, radius and angle | Force (N) · Radius (m) · Angle (deg) |
| LED Resistor Calculator | Calculate LED series resistor | Supply Voltage (V) · LED Voltage (V) · LED Current (mA) |
| Capacitor Calculator | Calculate capacitance | Charge (C) · Voltage (V) |
| Battery Life Calculator | Estimate battery life | Battery Capacity (mAh) · Consumption (mA) |
| Wire Gauge Calculator | Calculate wire gauge | Current (A) · Length (m) |
| RPM Calculator | Calculate rotational speed | Frequency (Hz) |
| Horsepower Calculator | Calculate horsepower | Torque (N·m) · RPM |
| Inductor Calculator | Calculate inductance | Number of Turns · Cross-section Area (m²) · Coil Length (m) |
| Impedance Calculator | Calculate RC/RL impedance | Resistance (Ω) · Reactance (Ω) |
| Beam Load Calculator | Calculate beam stress | Force (N) · Beam Length (m) · Moment of Inertia (m⁴) |
| Hydraulic Calculator | Calculate hydraulic pressure | Force (N) · Piston Area (m²) |
| Thermal Expansion | Calculate thermal expansion | Initial Length (m) · Expansion Coeff (1/°C) · Temp Change (°C) |
| kVA to kW Converter | Convert apparent power kVA to real power kW | Apparent Power (kVA) · Power Factor |
| Belt Length Calculator | Calculate V-belt length for two pulleys | Pulley 1 Diameter (mm) · Pulley 2 Diameter (mm) · Center Distance (mm) |
| Flow Rate Calculator | Calculate pipe flow rate from velocity and area | Pipe Diameter (mm) · Velocity (m/s) |
| Sound Level Addition | Add two sound levels in decibels | Sound 1 (dB) · Sound 2 (dB) |
| Shaft Power Calculator | Calculate power from torque and RPM | Torque (N·m) · RPM |
| Spring Rate Calculator | Calculate spring constant (Hooke's law) | Force (N) · Deflection (mm) |
| Resonant Frequency Calculator | Calculate LC circuit resonant frequency | Inductance (mH) · Capacitance (µF) |
| Transformer Ratio Calculator | Calculate transformer turns ratio | Primary Voltage (V) · Secondary Voltage (V) · Primary Turns |
| Hydraulic Power Calculator | Calculate pump hydraulic power | Flow (L/min) · Head (m) · Efficiency (%) |
| Stress & Strain Calculator | Calculate stress, strain and Young's modulus | Force (N) · Cross-section Area (mm²) · Original Length (mm) · Elongation (mm) |
| Beam Deflection (Simply Supported) | Max deflection of a uniformly loaded beam | Load (kN/m) · Length (m) · EI (kN·m²) |
| Euler Buckling Load | Critical load for column buckling | Young Modulus (GPa) · Moment of Inertia (mm⁴) · Effective Length (m) |
| Pipe Flow Rate (Darcy-Weisbach) | Pressure drop and velocity in pipe flow | Flow Rate (L/s) · Pipe Diameter (mm) · Pipe Length (m) · Friction Factor |
| Steel Weight Calculator | Weight of steel plates, bars, and tubes | Shape · Dimension 1 (mm) · Dimension 2 (mm) · Dimension 3 (mm) |
| Concrete Mix Design | Cement, sand, and gravel quantities for a mix | Volume (m³) · Mix Ratio |
| Structural Load Calculator | Dead, live, and wind load combinations (LRFD) | Dead Load (kN) · Live Load (kN) · Wind Load (kN) |
| Electrical Energy Cost | Electricity cost of an appliance | Appliance Wattage · Hours per Day · Rate ($/kWh) |
| Resistor Combination | Series and parallel resistance | Connection · R₁ (Ω) · R₂ (Ω) · R₃ (Ω) |
| Capacitor Energy | E = ½CV² energy stored in a capacitor | Capacitance (µF) · Voltage (V) |
| Inductor Energy | E = ½LI² energy stored in an inductor | Inductance (mH) · Current (A) |
| RC Time Constant | τ = RC for capacitor charging/discharging | Resistance (Ω) · Capacitance (µF) |
| Cable Sizing Calculator | Wire size from current and voltage drop | Current (A) · Cable Length (m) · Max Voltage Drop (%) · System Voltage (V) |
| Ventilation CFM Calculator | Airflow needed for room ventilation | Room Length (m) · Room Width (m) · Room Height (m) · Air Changes/Hour |
| Torque Wrench Setting | Adjusted torque when using an extension | Target Torque (Nm) · Wrench Length (mm) · Extension Length (mm) |
| Bearing Load Rating | Required dynamic load rating from bearing life | Dynamic Load (kN) · Speed (RPM) · Required Life (hrs) |
| Engine Efficiency Calculator | Thermal efficiency and BSFC | Power Output (kW) · Fuel Consumption (L/hr) · Fuel Heating Value (MJ/L) |
| Pump Power Calculator | Hydraulic power and motor size for pumps | Flow Rate (L/s) · Head (m) · Pump Efficiency (%) |
| Tank Volume Calculator | Volume of cylindrical and rectangular tanks | Shape · Radius or Width (m) · Length or Height (m) |
| Heat Exchanger (LMTD) | Log mean temperature difference method | Hot In (°C) · Hot Out (°C) · Cold In (°C) · Cold Out (°C) |
| PCB Trace Width Calculator | IPC-2221 trace width for a given current | Current (A) · Copper Thickness (oz) · Max Temp Rise (°C) |
| Bolt Torque Calculator | Clamping force from bolt torque | Applied Torque (Nm) · Bolt Diameter (mm) · K Factor (0.2 typical) |
| Pulley System Calculator | Effort needed with multiple pulley ropes | Load (N) · Supporting Ropes · Efficiency (%) |
| Lever Calculator | Fulcrum position or effort for a class-1 lever | Load (N) · Effort (N) · Load Arm (m) |
| Wind Load Calculator | Wind pressure and force on a surface | Wind Speed (km/h) · Surface Area (m²) · Drag Coefficient (Cd) · Air Density (kg/m³) |
| Duct Size Calculator | Round duct diameter from airflow and velocity | Airflow (CFM) · Target Velocity (ft/min) |
| Pipe Head Loss Calculator | Darcy–Weisbach friction head loss | Friction Factor (f) · Pipe Length (m) · Pipe Diameter (m) · Velocity (m/s) |
| Circuit Breaker Size Calculator | Breaker rating from continuous load | Continuous Load (W) · Voltage (V) |
| Power Factor Correction Calculator | kVAR capacitor needed to improve power factor | Real Power (kW) · Current PF · Target PF |
| Section Modulus Calculator | Elastic section modulus of a rectangle or circle | Shape · Width b (mm) · Height h / Diameter d (mm) |
| Shaft Torsion Stress Calculator | Shear stress in a solid circular shaft under torque | Torque T (N·m) · Shaft Diameter (mm) |
| Pulley Speed Calculator | Driven pulley rpm from the diameter ratio | Driver Diameter (mm) · Driver Speed (rpm) · Driven Diameter (mm) |
| Manning Flow Calculator | Full-pipe discharge via the Manning equation | Pipe Diameter (m) · Manning n (roughness) · Slope S (m/m) |
| Orifice Flow Calculator | Discharge through a sharp-edged orifice | Discharge Coefficient Cd · Orifice Diameter (m) · Head Above Orifice (m) |
| Three Phase Power Calculator | Real power of a balanced three-phase load | Line Voltage (V) · Line Current (A) · Power Factor (0–1) |
| UPS Battery Sizing Calculator | Battery amp-hours for a load and runtime target | Load (W) · Backup Time (minutes) · Battery Bank Voltage (V) · Inverter Efficiency (%) |
| Hydraulic Press Force Calculator | Output force from piston area ratio | Input Force (N) · Input Piston Area (sq in) · Output Piston Area (sq in) |
| Radiation Shielding Calculator | Intensity after absorber layers (half-value thickness) | Initial Intensity · Half-Value Layer (cm) · Shield Thickness (cm) |
| Steam Consumption Calculator | Heat delivered by steam flow at a given latent heat | Steam Flow (kg/h) · Latent Heat (kJ/kg) |
| Combined Noise Level Calculator | Logarithmic sum of simultaneous sound sources | Source 1 (dB) · Source 2 (dB) |
| RCF (G-Force) Calculator | Relative centrifugal force from rpm and rotor radius | Rotor Speed (rpm) · Rotor Radius (cm) |
| Pipe Pressure Loss Calculator | Free pipe pressure loss calculator using the Hazen-Williams equation: head loss and PSI drop by pipe material, flow and diameter. | Flow rate (gpm) · Internal diameter (in) · Pipe material · Pipe length (ft) |
| HVAC Load Calculator | Free simplified HVAC cooling load calculator: BTU per hour and tons of cooling from floor area, climate, insulation and windows. | Conditioned floor area (sq ft) · Climate · Insulation quality · Number of windows |
Prefer the annotated list? Browse the full list with one line on what each calculator does.
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