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Engineering Calculators
Structural, mechanical, and fluid engineering tools. 80 free calculators — no sign-up required.
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Boiler Feed Pump Calculator
Size boiler feed pumps, feed tanks, and check NPSH for safe operation. Calculate flow rate, total head, power requirements, tank capacity, and cavitation risk. Complete guide with ASME standards and energy optimization.
Amps to kW Calculator
Convert amps to kilowatts for DC, AC single-phase, and AC three-phase circuits. Includes power factor, line-to-line and line-to-neutral voltage, kW to amps, amps plus ohms, kVA, watts, horsepower, and kWh estimates.
kW to Amps Calculator
Convert kilowatts to amps for DC, AC single-phase, and AC three-phase circuits using voltage, power factor, and efficiency. Includes amps to kW, kVA to amps, formulas, examples, tables, and FAQs.
Amps to Watts Calculator
Convert amps to watts for DC, AC single-phase, and AC three-phase circuits using voltage and power factor. Includes watts to amps, amps plus ohms, kW, kVA, horsepower, kWh, formulas, examples, tables, and FAQs.
Power Factor Calculator
Calculate power factor from kW and kVA or from watts, volts, and amps. Includes kW, kVA, kVAR, apparent power, reactive power, phase angle, power factor correction kVAR, formulas, examples, tables, and FAQs.
Decoupling Capacitor Calculator
Calculate decoupling capacitor values for IC power supply filtering. Design multi-layer capacitor networks (bulk, ceramic) to manage power distribution noise, ESR, and transient response in digital circuits.
kVA to Amps Calculator
Convert kVA to amps and amps to kVA for single-phase and three-phase AC circuits, with line-to-line and line-to-neutral voltage options, power factor estimates, charts, and examples.
LC Tank Resonance Calculator
Calculate resonant frequency from inductance and capacitance, or solve for L or C given frequency. Includes Q factor, bandwidth, impedance, and tank circuit design formulas for oscillators and RF filters.
Voltage Regulator Dropout Calculator
Calculate linear regulator (LDO) dropout voltage, power dissipation, thermal effects, and heat sink requirements. Design power supplies with efficiency and thermal stability analysis.
kW to kVA Calculator
Convert kW to kVA, kVA to kW, and calculate power factor. Includes generator, transformer, motor, and three-phase examples with optional current estimate.
Generator Current Calculator
Calculate generator output current from kVA or kW rating, or estimate generator size from load amps. Supports single-phase and three-phase generators, power factor, voltage presets, and reserve capacity.
Motor Inrush Current Calculator
Calculate motor starting (inrush) current, thermal demand, and soft-starter/VFD sizing. Design protection circuits for AC induction motors.
Motor Current Calculator
Estimate motor full-load current from kW or horsepower, voltage, phase, power factor, and efficiency. Supports DC, single-phase AC, and three-phase AC motors.
Relay Coil Power Calculator
Calculate relay coil power consumption, pull-in/hold current, contact rating, and snubber resistor sizing for control circuits.
3 Phase Current Calculator
Calculate three-phase current from kW or kVA, or calculate three-phase kW and kVA from amps. Supports line-to-line and line-to-neutral voltage, power factor, and common voltages.
NTC Thermistor Calculator
Calculate NTC thermistor resistance at various temperatures using Beta equation and Steinhart-Hart models. Design temperature-sensing circuits.
Ferrite Bead Impedance Calculator
Calculate ferrite bead impedance at RF frequencies for EMI/RFI filtering in high-speed circuits.
Zener Diode Resistor Calculator
Calculate the series resistor, resistor wattage, Zener current, and Zener power for a simple Zener diode shunt regulator.
Voltage Divider Calculator
Calculate unloaded and loaded voltage divider output, divider current, Thevenin resistance, and resistor values for a target voltage.
LED Resistor Calculator
Calculate the current-limiting resistor, resistor wattage, LED branch current, and total LED power for single, series, and parallel LED circuits.
SMD Resistor Code Calculator
Decode 3-digit, 4-digit, R-notation, zero-ohm, and EIA-96 SMD resistor markings into resistance values.
Battery Life Calculator
Estimate battery runtime from mAh, load current, duty cycle, Wh, efficiency, and usable battery capacity.
Buck Converter Inductor Calculator
Estimate buck converter inductance, ripple current, peak inductor current, duty cycle, input current, and stored energy from Vin, Vout, current, frequency, and ripple target.
Op-Amp Gain Calculator
Calculate inverting and non-inverting op-amp voltage gain, gain in dB, output voltage, and feedback resistor values from common resistor networks.
LC Resonant Frequency Calculator
Calculate LC resonant frequency, required inductance, required capacitance, angular frequency, period, and reactance at resonance.
Capacitive Reactance Calculator
Calculate capacitive reactance, capacitance, frequency, impedance form, and AC current estimate for capacitor circuits.
Inductive Reactance Calculator
Calculate inductive reactance, inductance, frequency, impedance form, and AC current estimate for inductor circuits.
Moment of Inertia Calculator
Calculate area moment of inertia, section modulus, area, centroid, and radius of gyration for rectangles, tubes, circles, and simple built-up I sections.
Mohr's Circle Calculator
Calculate Mohr's circle center, radius, principal stresses, maximum in-plane shear stress, and transformed stress at a selected plane angle.
Rock Mass Rating Calculator
Estimate Bieniawski Rock Mass Rating from strength, RQD, discontinuity spacing, discontinuity condition, groundwater, and orientation adjustment.
Span Calculator for Joists
Estimate allowable joist span from spacing, load, section size, modulus of elasticity, allowable bending stress, and deflection limit.
Angle Iron Load Capacity Calculator
Estimate angle iron load capacity from equal-leg angle geometry, span, support condition, steel stress limit, and deflection limit.
Angle of Repose Calculation
Calculate angle of repose from pile height and radius, coefficient of static friction, slope percent, or direct angle input.
Belleville Disc Spring Calculator
Estimate Belleville disc spring force, flat load, stack travel, and approximate spring rate from disc geometry, material, and stacking arrangement.
Bend Radius Calculator (Pipe)
Calculate pipe bend centerline radius, inside/outside radius, bend arc length, tangent length, and bend ratio from pipe OD and bend angle.
Boiler Feed Pump Calculation
Estimate boiler feed pump flow, discharge pressure, head, hydraulic horsepower, and motor horsepower from boiler load and operating pressure.
Boiler HP to Lbs/Hr Calculator
Convert boiler horsepower to pounds per hour of steam, kg/hr, BTU/hr, kW, and feedwater GPM estimate.
Box Compression Test Strength Calculator
Estimate corrugated box compression strength using the simplified McKee equation, humidity derating, and stacking safety factor.
Brake Press Tonnage Calculator
Estimate press brake air-bending tonnage from sheet thickness, V-die opening, bend length, material tensile strength, and safety factor.
Brake Press Tonnage Calculator
Estimate press brake air-bending tonnage from sheet thickness, V-die opening, bend length, material tensile strength, and safety factor.
Brake System Pressure Calculator
Calculate brake hydraulic line pressure, master cylinder area, caliper clamp force, and estimated wheel brake torque from pedal and caliper inputs.
Brake System Pressure Calculator
Calculate brake hydraulic line pressure, master cylinder area, caliper clamp force, and estimated wheel brake torque from pedal and caliper inputs.
Conduit Bending Calculator
Calculate conduit offset bend spacing, shrink allowance, layout marks, and 90-degree stub-up mark from practical field inputs.
Conduit Bending Calculator
Calculate conduit offset bend spacing, shrink allowance, layout marks, and 90-degree stub-up mark from practical field inputs.
Controllability Check Calculator
Check the Kalman controllability matrix rank for a linear state-space system from A and B matrices.
Controllability Check Calculator
Check the Kalman controllability matrix rank for a linear state-space system from A and B matrices.
Pipe Weight Calculator
Calculate round pipe weight from OD, wall thickness, length, quantity, and material density with kg/m, lb/ft, and total weight outputs.
Pipe Weight Calculator
Calculate round pipe weight from OD, wall thickness, length, quantity, and material density with kg/m, lb/ft, and total weight outputs.
How to Calculate Roof Pitch
Calculate roof pitch from rise and run or angle, including pitch ratio, degrees, percent slope, multiplier, rafter length, and roof area.
How to Calculate Roof Pitch
Calculate roof pitch from rise and run or angle, including pitch ratio, degrees, percent slope, multiplier, rafter length, and roof area.
Angle of Repose Calculator
Calculate angle of repose from pile height and radius or diameter, with tangent, slope percent, and friction estimate.
V1 VR V2 Calculator (A330)
Educational A330 V1, VR, and V2 training estimator using reference speeds, weight scaling, and manual corrections with strong flight-use warnings.
V1 VR V2 Calculator (A330)
Educational A330 V1, VR, and V2 training estimator using reference speeds, weight scaling, and manual corrections with strong flight-use warnings.
Brass Rod Weight Calculator
Calculate brass round rod, square bar, hex bar, and flat bar weight from dimensions, length, quantity, and density.
Brass Rod Weight Calculator
Calculate brass round rod, square bar, hex bar, and flat bar weight from dimensions, length, quantity, and density.
Aluminum Coil Weight Calculator
Calculate aluminum coil weight and estimated strip length from OD, ID, width, thickness, density, and quantity.
Aluminum Coil Weight Calculator
Calculate aluminum coil weight and estimated strip length from OD, ID, width, thickness, density, and quantity.
Air Filter Pressure Drop Calculation
Estimate HVAC or process air filter pressure drop from rated pressure drop, airflow ratio, filter area, number of filters, and loading multiplier.
Air Filter Pressure Drop Calculation
Estimate HVAC or process air filter pressure drop from rated pressure drop, airflow ratio, filter area, number of filters, and loading multiplier.
Air Flow Through an Orifice Calculator
Estimate subsonic air flow through a round orifice from diameter, pressure difference, air density, and discharge coefficient.
Air Flow Through an Orifice Calculator
Estimate subsonic air flow through a round orifice from diameter, pressure difference, air density, and discharge coefficient.
Air to Cloth Ratio Calculator
Calculate baghouse air-to-cloth ratio, net cloth area, required cloth area, and estimated bag count from airflow and filter dimensions.
Air to Cloth Ratio Calculator
Calculate baghouse air-to-cloth ratio, net cloth area, required cloth area, and estimated bag count from airflow and filter dimensions.
Adiabatic Lapse Rate Calculator
Estimate final air temperature from height change using dry, moist, standard, or custom lapse rates.
Adiabatic Lapse Rate Calculator
Estimate final air temperature from height change using dry, moist, standard, or custom lapse rates.
Booster Pump Sizing Calculator
Estimate booster pump flow, total dynamic head, hydraulic power, and shaft horsepower with pressure and margin inputs.
Booster Pump Sizing Calculator
Estimate booster pump flow, total dynamic head, hydraulic power, and shaft horsepower with pressure and margin inputs.
Mini Split Sizing Calculator
Estimate ductless mini split BTU size from room area, ceiling height, climate, insulation, sun, people, and heat load.
Mini Split Sizing Calculator
Estimate ductless mini split BTU size from room area, ceiling height, climate, insulation, sun, people, and heat load.
Feeds and Speeds Calculator
Calculate spindle RPM, feed rate, chip load relationship, and material removal rate for machining estimates.
Feeds and Speeds Calculator
Calculate spindle RPM, feed rate, chip load relationship, and material removal rate for machining estimates.
How to Calculate Gear Ratio
Calculate simple or compound gear ratio, output speed, and output torque from gear teeth, RPM, torque, and efficiency.
How to Calculate Gear Ratio
Calculate simple or compound gear ratio, output speed, and output torque from gear teeth, RPM, torque, and efficiency.
Cycles per Instruction Calculator
Calculate average CPI from CPU cycles, instruction count, clock rate, CPU time, or a weighted instruction mix.
Septic Tank Size Calculator
Estimate septic tank capacity from bedrooms, occupants, daily wastewater flow, detention time, reserve allowance, and local minimum size.
Acrylic Aquarium Thickness Calculator
Estimate acrylic aquarium panel thickness using water height, panel span, support condition, allowable stress, and safety factor.
Ball Nose Step Over Calculator
Calculate ball nose scallop height from stepover or calculate stepover from a target cusp height for CNC finishing.
B Series Compression Calculator
Calculate static compression ratio for B-series engine builds from bore, stroke, chamber, gasket, piston, and deck measurements.
Calculate Bending When Have Angle
Calculate sheet metal bend allowance, setback, bend deduction, and flat pattern length when the bend angle is known.
ADA Ramp Slope Calculator
Calculate ADA ramp run length, slope percentage, ramp angle, and number of runs from rise and slope ratio.