Free Online Electrical & Electronics Calculators

ADC/DAC & Digital Calculators cover the math behind analog-to-digital conversion and digital logic design. Calculate ADC resolution, ADC ENOB, ADC SNR, and ADC spurious performance for data converter specs, or work through a DAC calculator for the reverse conversion. The Nyquist frequency calculator sets sampling rate requirements, while bit shift, bitwise, and parity bit calculators handle low-level binary operations.

This section also includes a Boolean algebra simplifier, Karnaugh map (K-map) calculator, and logic gate truth table calculator for digital logic design, plus a number system converter, hex to ASCII converter, and CRC calculator for data encoding and error checking.

Attenuator Calculators help you design resistive networks that reduce signal power by a precise amount. Calculate a Pi attenuator, Tee attenuator, or bridged Tee attenuator for RF and audio circuits, or use the L-pad attenuator calculator for impedance-matched signal reduction. The balanced attenuator and step attenuator calculators cover more specialized attenuation needs, while the reflection attenuator calculator and RF power conversion calculator round out RF signal chain design.

Audio & Acoustics Calculators cover speaker, amplifier, and room design for audio systems. Calculate amplifier power and speaker impedance to match components safely, or size a speaker enclosure volume and design a speaker crossover for multi-driver systems. The speaker wire gauge calculator and audio attenuator (L-pad) calculator handle wiring and level matching.

This section also includes a decibel SPL calculator, equalizer frequency calculator, and room acoustics calculator for tuning sound in a physical space.

Basic Circuit Laws Calculators cover the foundational theorems every circuit analysis starts with. Apply Kirchhoff's Current Law (KCL) and Kirchhoff's Voltage Law (KVL) to solve for unknown currents and voltages, or use Thevenin's theorem, Norton's theorem, and superposition theorem to simplify complex circuits. The maximum power transfer calculator finds the load that draws the most power from a source, Millman's theorem calculator solves multi-source parallel circuits, and the Watts-Volts-Amps-Ohms calculator ties the basic relationships together.

Batteries & Energy Storage Calculators help you size and manage battery systems for any application. Calculate battery life, battery charge time, and battery discharge rate, or size a battery bank with the battery bank sizing calculator and battery series/parallel calculator. Chemistry-specific tools include the lead-acid battery calculator and lithium-ion battery calculator, while Peukert's Law calculator adjusts capacity estimates for high discharge rates.

This section also includes a battery depth of discharge calculator, battery state of charge calculator, battery internal resistance calculator, and a UPS runtime calculator for backup power planning.

Capacitor Calculators cover sizing, charge behavior, and identification for every type of capacitor. Calculate capacitor charge, capacitor discharge, and capacitor impedance, or read a capacitor's value from its code with the capacitor value/code calculator. Capacitors in parallel and a capacitor voltage divider calculator handle multi-capacitor circuits, while the decoupling capacitor calculator and supercapacitor sizing calculator cover power supply filtering and energy storage.

This section also includes parallel plate, cylindrical, and spherical capacitor calculators for physics-based capacitance from geometry, plus a capacitor ripple current calculator for switching power supply design.

Communication & Networking Calculators cover the data rate and signal budget math behind wired and wireless links. Calculate bandwidth to data rate, data transfer rate, and Ethernet cable performance, or work out a Bluetooth range and LoRa link budget for wireless connections. Serial and bus protocols are covered by the SPI clock calculator, I2C pull-up resistor calculator, CAN bus termination calculator, Modbus RTU calculator, and serial communication calculator.

This section also includes a fiber optic loss calculator for optical networking design.

Electrical Conversion Calculators handle every common unit switch in electrical engineering. Convert between volts, amps, watts, and VA with tools like volts to amps, amps to watts, watts to volts, and VA to watts calculators, or work with power ratios using the decibel (dB), dBm to watts, and dBW to watts calculators. Energy unit conversions include watts to joules, joules to watts, kWh to kW, kW to kWh, Wh to mAh, and mAh to Wh calculators.

This section also covers larger power units with amps to kVA, amps to kW, kVA to kW, kW to kVA, kVA to amps, and kW to amps calculators, plus frequency to period, frequency to wavelength, volts to eV, eV to volts, and volts to joules calculators for RF and physics-adjacent conversions.

Electrical Installation Calculators cover the sizing and code compliance work behind residential and commercial wiring. Calculate electrical load and demand factor for a building, or size a service entrance and feeder with the service entrance calculator and feeder sizing calculator. The NEC wire size calculator and motor branch circuit calculator apply National Electrical Code requirements to specific circuits.

This section also includes a box fill calculator, raceway fill calculator, panel schedule calculator, and receptacle load calculator for panel and conduit planning.

Electrical Safety & Protection Calculators help you design circuits that protect people and equipment from electrical hazards. Calculate arc flash energy and short circuit current for equipment labeling and PPE selection, or size a fuse rating and check RCD/GFCI trip thresholds for overcurrent and ground fault protection. The ground fault calculator and ground rod resistance calculator cover grounding system design.

This section also includes a touch voltage/step voltage calculator, lightning protection calculator, surge protector rating calculator, cable derating calculator, and an IP rating calculator for enclosure protection ratings.

Electromagnetism Calculators cover the field theory equations behind electricity, magnetism, and their interaction. Apply Coulomb's Law, Gauss's Law, and Ampere's Law to calculate electric and magnetic fields, or use the Biot-Savart Law calculator and Lorentz force calculator for more complex field and force problems. Faraday's Law/EMF calculator and Lenz's Law calculator cover electromagnetic induction, while the magnetic flux, magnetic field of straight wire, and solenoid magnetic field calculators handle common magnetic geometries.

This section also includes electric potential, electric field, dipole moment, and magnetic dipole moment calculators, plus specialized tools like skin depth, Hall coefficient, cyclotron frequency, drift velocity, intrinsic carrier concentration, and magnetic permeability calculators for semiconductor and advanced electromagnetics work.

Filter Calculators help you design circuits that pass or block specific frequency ranges. Calculate a Butterworth filter, Chebyshev filter, or Bessel filter for different frequency response characteristics, or design a band pass filter, band stop/notch filter, or active filter for a specific application. The Sallen-Key filter calculator and LC filter calculator cover common active and passive filter topologies.

This section also includes a Pi filter calculator and EMI filter calculator for power supply and noise suppression filtering.

Inductor Calculators cover sizing, winding, and identification for coils used in power and RF circuits. Calculate air core inductor and solenoid inductance values from coil geometry, or design a toroidal inductor and ferrite core inductor for compact, shielded designs. The inductor color code calculator reads component values from color bands, while inductor impedance and inductors in series calculators handle circuit-level calculations.

This section also includes a mutual inductance calculator and wire self-inductance calculator for coupled and single-conductor inductance.

Lighting Calculators cover the photometric conversions and sizing math behind LED and general lighting design. Convert between lumens, watts, and lux with the lumens to watts, watts to lumens, and lux to lumens calculators, or calculate luminous flux and color temperature for a specific fixture. The LED driver calculator and LED strip power calculator size power supplies for LED lighting.

This section also includes a beam angle calculator, lighting layout calculator, and emergency lighting calculator for code-compliant lighting design.

Motors & Drives Calculators size and analyze electric motors and the drives that control them. Calculate motor sizing, motor torque, and motor efficiency, or estimate motor full load amps and motor starting current for circuit protection sizing. The VFD (variable frequency drive) calculator and DC motor speed control calculator cover speed control methods, while stepper motor and servo motor sizing calculators support precision motion applications.

This section also includes a motor slip calculator, motor power factor calculator, motor protection calculator, motor speed calculator, and gear ratio and speed calculator for mechanical power transmission.

Op-Amp Calculators cover the standard amplifier and signal-conditioning circuits built around operational amplifiers. Calculate op-amp gain for an inverting amplifier, non-inverting amplifier, or differential amplifier, or design a summing amplifier and instrumentation amplifier for multi-input or precision applications. The integrator circuit and differentiator circuit calculators cover analog signal processing, while comparator and Schmitt trigger calculators handle threshold detection.

This section also includes op-amp bandwidth, op-amp noise, and op-amp slew rate calculators for performance limits, plus voltage follower/buffer, transimpedance amplifier, and active rectifier calculators for specialized op-amp configurations.

PCB Design Calculators cover the trace geometry and signal integrity math behind printed circuit board layout. Calculate microstrip line and stripline impedance for controlled-impedance traces, or design a coplanar waveguide and differential microstrip for RF and high-speed digital signals. The PCB trace current and PCB trace resistance calculators size copper traces for current-carrying capacity, while via current capacity and via impedance calculators handle layer-to-layer connections.

This section also includes a crosstalk calculator, signal propagation delay calculator, copper weight to thickness calculator, PCB thermal via calculator, and decoupling capacitor placement calculator for signal integrity and thermal design.

Power Calculators cover the fundamental electrical power equations used across every electrical discipline. Calculate AC power and DC power directly, or work with three-phase power for industrial and commercial systems. The power factor correction calculator estimates capacitor sizing to improve efficiency, while watts to kWh and kWh to watts calculators convert between instantaneous power and energy consumption.

This section also includes a power density calculator and horsepower to watts calculator for mechanical-to-electrical power conversions.

Power Supply & Regulators Calculators cover the design of switching and linear power conversion circuits. Design a buck converter, boost converter, or buck-boost converter for DC-DC conversion, or calculate a flyback converter, forward converter, and SEPIC converter for isolated and specialized topologies. Linear regulator design is covered by the LM317 voltage regulator, LM7805/78xx regulator, LM7905/79xx regulator, and linear dropout regulator (LDO) calculators.

This section also includes a smoothing capacitor calculator, snubber circuit calculator, crowbar circuit calculator, inrush current limiter calculator, charge pump calculator, and voltage regulator heat sink calculator for supporting power supply components.

RC/RL/RLC Circuit Calculators cover the time-domain and frequency-domain behavior of resistor-capacitor-inductor circuits. Calculate the time constant of an RC or RL circuit, or find the resonant frequency and quality factor (Q) of an RLC series or RLC parallel circuit. The damping factor calculator and phase angle calculator describe how a circuit responds to a changing signal, while the LC tank circuit calculator covers pure resonant circuits.

This section also includes a bandwidth calculator and admittance calculator for frequency-response analysis.

RF & Microwave Calculators cover antenna design, link budgets, and transmission line math for wireless and radar systems. Calculate a link budget with the Friis transmission equation, or design a Yagi-Uda antenna, helical antenna, parabolic antenna, or microstrip patch antenna for a specific gain and frequency. The reflection coefficient, return loss, and Smith chart calculators analyze impedance matching, while the coax cable loss calculator and waveguide calculator handle transmission line losses.

This section also covers radar and safety calculations: radar range equation, radar cross section, SAR calculator (specific absorption rate), noise temperature, minimum detectable signal, and RF power density calculators, plus a Wilkinson power divider, directional coupler, mixer spur, SFDR, and varactor diode tuning calculator for RF front-end design.

Resistor Calculators cover identification, combination, and specification of resistors in any circuit. Read a resistor's value from its color bands with the 4-band, 5-band, and 6-band resistor color code calculators, or the SMD resistor code calculator for surface-mount parts. Calculate resistors in series and resistors in parallel, or design a resistor network, potentiometer, or pull-up/pull-down resistor for a specific circuit function.

This section also includes a preferred resistor value calculator, shunt resistor calculator, resistivity calculator, and temperature coefficient of resistance calculator for precision and high-power resistor applications.

Sensors & Measurement Calculators cover the signal conditioning math behind common industrial and lab sensors. Calculate temperature from a thermocouple, RTD, or thermistor reading, or convert a strain gauge or load cell output into a physical measurement. The accelerometer calculator and pressure sensor calculator handle motion and pressure sensing, while the current sense resistor calculator sizes shunt resistors for current measurement.

This section also includes an ultrasonic distance calculator and pH meter calibration calculator for other common sensing applications.

Signals & Waveforms Calculators analyze the shape, timing, and quality of electrical signals. Calculate duty cycle and PWM parameters for pulse-width modulated signals, or find peak-to-peak voltage, average voltage, and crest factor for any waveform. The rise time/fall time calculator and phase noise to jitter calculator characterize signal timing, while signal-to-noise ratio (SNR) and total harmonic distortion calculators assess signal quality.

This section also includes a baud rate calculator, form factor calculator, and FFT frequency resolution calculator for digital communication and spectral analysis.

Solar & Renewable Energy Calculators for electrical systems help you design and size solar and wind power installations. Size a grid-tied solar system or off-grid solar system, or calculate solar panel sizing, solar panel efficiency, and solar panel angle/tilt for optimal energy capture. The solar inverter sizing and solar charge controller calculators size the equipment that converts and manages solar power, while the solar panel string calculator plans series/parallel panel wiring.

This section also includes a wind speed to power calculator and wind turbine power calculator for wind energy systems, plus a solar insolation calculator and solar ROI calculator for site assessment and payback analysis.

Thermal Management Calculators help you keep electronic components within safe operating temperatures. Calculate heat sink requirements and junction temperature for a power semiconductor, or estimate fan airflow needed to cool an enclosure. The derating calculator and power MOSFET thermal calculator size components for safe continuous operation, while the Peltier/TEC calculator covers thermoelectric cooling and the PCB thermal relief calculator addresses heat dissipation on circuit boards.

Three-Phase Systems Calculators cover the specialized math behind three-phase power distribution. Calculate three-phase voltage, three-phase current, and three-phase kVA, or convert between delta and star (wye) configurations with the delta to star and star to delta conversion calculators. The three-phase load balancing calculator checks for uneven loading across phases, while the per-unit system calculator and symmetrical components calculator support power system analysis and fault calculations.

Timer & Oscillator Circuit Calculators cover the classic circuits used to generate timing signals and clock frequencies. Design a 555 timer in astable, monostable, or PWM configuration, or calculate a crystal oscillator, Colpitts oscillator, Hartley oscillator, or Wien bridge oscillator for a specific frequency. The VCO (voltage controlled oscillator) calculator and ring oscillator calculator cover variable-frequency designs, while PLL loop filter and PLL PFD frequency calculators support phase-locked loop circuits.

This section also includes a phase shift oscillator calculator and relaxation oscillator calculator for other common oscillator topologies.

Transformer Calculators cover the design and analysis of transformers used in power and signal applications. Calculate transformer turns ratio and transformer impedance, or estimate transformer efficiency after accounting for transformer copper loss and transformer core loss. The current transformer ratio calculator and auto-transformer calculator cover specialized transformer types, while the flyback transformer calculator and RF transformer calculator support switching power supply and RF designs.

This section also includes a transformer winding calculator for turns and wire gauge planning.

Transistors & Semiconductors Calculators cover biasing, switching, and power dissipation for common semiconductor devices. Calculate transistor biasing and a BJT amplifier's gain, or size a MOSFET and calculate MOSFET gate charge and MOSFET power dissipation for switching applications. The diode forward voltage, Zener diode, and photodiode calculators cover diode-based circuits, while full-wave rectifier and half-wave rectifier calculators convert AC to DC.

This section also includes SCR/thyristor, TRIAC, IGBT loss, JFET, and Darlington pair calculators for power switching devices, plus an LED series/parallel array calculator for designing LED circuits with the right current-limiting resistors.

Wiring & Cables Calculators help you size and specify cables for safe, code-compliant installations. Calculate wire size/AWG and cable ampacity for a given current and length, or estimate wire temperature rise under continuous load. The conduit fill calculator and cable tray fill calculator determine how many cables can safely share a raceway, while coaxial cable and twisted pair cable calculators cover data and RF cabling.

This section also includes a wire pull tension calculator and cable length calculator (TDR) for cable installation and fault-location work.