Engineering & Electronics
Engineering and electronics tools: Ohm's law, resistor and capacitor networks, power, wire sizing, beams, pumps and flow. They give quick design estimates; check critical work against the applicable standard or a qualified engineer.
207 tools · page 1 of 4
- Transformer Turns Ratio Calculator Calculate transformer secondary voltage and current from the primary voltage and turns ratio.
- Parallel Resistance Calculator Calculate the total resistance of two or three resistors connected in parallel.
- Gear Ratio Calculator Calculate the gear ratio between a driving and a driven gear. Enter the number of teeth on each gear to get the ratio, whether it is a reduction or overdrive, and the resulting output speed at 1000 input RPM.
- Inductive Reactance Calculator Calculate the inductive reactance of an inductor at a given frequency.
- Pulley Speed Ratio Calculator Calculates the driven pulley's RPM and the speed ratio from the driver and driven pulley diameters and the driver's RPM.
- Solenoid Inductance Calculator Calculate the inductance of a solenoid from turns, cross-sectional area, length and core permeability.
- Parallel-Plate Capacitor Calculator Calculate the capacitance of a parallel-plate capacitor from plate area, gap and dielectric constant.
- Capacitor Energy Calculator Calculate the energy and charge stored in a capacitor (E=½CV²).
- Ohm's Law Power Calculator Calculate electrical power and resistance from voltage and current using Ohm's law.
- LC Resonant Frequency Calculator Calculate the resonant frequency of an LC circuit.
- Ohm’s Law Calculator Enter any two of voltage, current and resistance to find the remaining value and the power, using Ohm’s law.
- RC Time Constant Calculator Calculate the RC time constant and charge time.
- Capacitors in Series Calculator Calculate the total capacitance of two or three capacitors connected in series.
- Antenna Length Calculator Calculate full, half and quarter-wave antenna lengths from a frequency in MHz.
- Parking Lot Stalls Calculator Estimate how many parking stalls fit in a lot from its area and the area per stall including aisles.
- Resistor Color Code Calculator Read the resistance value of a 4-band resistor from its color bands. Pick the two digit colors, the multiplier color, and the tolerance color to instantly get the resistance in Ω, kΩ, or MΩ, the tolerance percentage, and the minimum–maximum value range.
- Series Resistance Calculator Add resistors connected in series to find the total equivalent resistance (Rtotal = R1 + R2 + R3 + R4).
- Solar Panel Output Calculator Estimate how much electricity a solar panel system produces. Enter your system size in kW, your local peak sun hours per day, and a system derate factor to get daily, monthly, and yearly kWh output.
- VSWR Calculator Calculate VSWR and return loss from the reflection coefficient.
- Inductor Energy Calculator Calculate the energy stored in an inductor from its inductance and current.
- Op-Amp Gain Calculator Calculate the non-inverting and inverting gain of an op-amp from the feedback and input resistors.
- Decibel (dB) Gain Calculator Calculate power gain in decibels from two power levels.
- Horsepower from Torque Calculator Calculate engine horsepower from torque (lb-ft) and RPM, with the kilowatt equivalent.
- dBm to Watts Calculator Convert power from dBm to watts and milliwatts.
- RLC Impedance Calculator Calculate the impedance, reactances and resonant frequency of a series RLC circuit.
- Voltage Divider Calculator Calculate the output voltage of a resistor voltage divider.
- Capacitor Charge Calculator Calculate the charge stored on a capacitor and its energy from capacitance and voltage.
- Wire Resistance Calculator Calculate wire resistance from length, cross-section and material.
- dB Attenuation Calculator Calculate signal attenuation in decibels from input and output power.
- Cutting Speed Calculator Calculate machining surface (cutting) speed from tool/work diameter and spindle RPM.
- Snow Load Calculator Calculate the snow load on a roof from snow depth, snow density, and roof area. Get the load per square meter (kg/m²), the total weight on the roof (kg), and the pressure in kilopascals (kPa) to help check structural safety.
- Capacitor Impedance at Frequency Find the impedance (capacitive reactance Xc) of a capacitor at a given frequency: Xc = 1 / (2πfC).
- LED Resistor Calculator Calculate the series resistor an LED needs from your supply voltage, the LED forward voltage and the target current. Get the exact resistance, the power the resistor dissipates, and the nearest E12 standard value to buy.
- Current Divider Calculator Calculate how current splits between two parallel resistors.
- Pulley Mechanical Advantage Calculator Calculate the mechanical advantage and effort force of a pulley system from the supporting rope segments.
- Flow Rate Calculator Calculate the volumetric flow rate from cross-sectional area and flow velocity.
- Decibel Voltage Ratio Calculator Computes the gain in decibels of a voltage ratio using 20·log10(Vout/Vin), the standard amplitude (field-quantity) dB definition.
- Parallel Resistance Calculator (Multiple) Find the equivalent resistance of up to four resistors wired in parallel using 1/Rₜ = 1/R₁ + 1/R₂ + 1/R₃ + 1/R₄. Only the first resistor is required; leave any of R₂–R₄ blank to use fewer resistors. Also shows total conductance.
- Solar Panel Count Calculator Estimate how many solar panels you need from daily energy use, panel wattage, peak sun hours, and system efficiency.
- Power Factor Correction Calculator Calculate the capacitor reactive power needed to correct a system's power factor.
- Belt Speed Calculator Compute the linear belt speed from the pulley diameter and rotational speed.
- Gain (dBi) to Gain (dBd) Converter Convert gain (dbi) to gain (dbd) instantly with this fast, accurate unit converter.
- RMS to Peak Voltage Calculator Convert RMS voltage to peak and peak-to-peak. RMS to Peak Voltage Calculator gives you the result instantly from a simple input.
- Wind Pressure Calculator Calculate the dynamic wind pressure on a surface from wind speed: q = 0.613 × v² (pressure in pascals, speed in m/s). Useful for estimating loads on signs, panels, fences and structures.
- Rebar Weight Calculator Calculate the total weight of steel reinforcement bars from diameter, length, and quantity (d²/162).
- Bolt Torque Calculator Calculate the tightening torque for a bolt from the nut factor, diameter and target clamp force.
- Resistor Power Dissipation Calculator Calculates the power a resistor dissipates as heat using P = I²R, helping you choose a resistor with an adequate power rating.
- Capacitive Reactance Calculator Calculate the capacitive reactance of a capacitor at a given frequency.
- Battery Runtime Calculator Calculate battery runtime from capacity (Ah), voltage, load (W), and usable depth of discharge. Returns runtime in hours and minutes plus usable energy in watt-hours.
- Decibel to Linear Calculator Converts a decibel value to its linear ratio using the power (10^(dB/10)) or field (10^(dB/20)) formula.
- Air-Core Coil Inductance Calculator Estimates the inductance of a single-layer air-core coil from its diameter, length and turns using Wheeler's formula.
- Conductance Calculator Calculate electrical conductance, G = 1/R, in siemens and millisiemens from a resistance. The reciprocal of resistance.
- Inverting Op-Amp Gain Calculator Calculate the gain of an inverting operational amplifier from the feedback and input resistors, plus the output voltage for a given input.
- Inductors in Parallel Calculator Computes the total inductance of two to four inductors connected in parallel using 1/Lt = Σ 1/Li.
- Peak-to-Peak Voltage Calculator Find peak-to-peak and RMS voltage from amplitude. Peak-to-Peak Voltage Calculator gives you the result instantly from a simple input.
- Potentiometer Output Voltage Calculator Calculate the output (wiper) voltage of a potentiometer used as a voltage divider, from the input voltage and the wiper position as a percentage of full travel. Assumes a high-impedance (unloaded) output.
- kVA to Amps Calculator Convert apparent power in kVA to current in amps. kVA to Amps Calculator gives you the result instantly from a simple input.
- Skin Depth Calculator Calculate the skin depth of an alternating current in a conductor from resistivity and frequency.
- Venturi Meter Flow Rate Calculator Calculates volumetric flow rate through a venturi meter from inlet and throat diameters, pressure differential, fluid density and discharge coefficient.
- Wing Loading Calculator Calculate wing loading — total weight divided by wing area — a key figure in aircraft and drone design that affects stall speed, manoeuvrability and ride in turbulence.