Electronics Calculators

Our electronics calculators speed up circuit design and analysis with tools for Ohm's law, resistor color codes, voltage dividers, LED resistors, and power dissipation. Whether you are prototyping or studying, they deliver precise values for reliable, working circuits.

555 Timer Calculator

Calculate frequency, period, and duty cycle for a 555 timer in astable mode.

Active Filter Calculator

Design Butterworth, Chebyshev, and Bessel active filters with Sallen-Key or MFB topologies. Get component values snapped to E96/E24 standard resistors with Bode plot visualization.

Antenna Length Calculator

Calculate quarter-wave, half-wave dipole, and full-wavelength antenna lengths from frequency.

Capacitive Reactance Calculator

Calculate the capacitive reactance (XC) of a capacitor from frequency and capacitance.

Capacitor Energy Calculator

Calculate the energy and charge stored in a capacitor from its capacitance and voltage.

dBm to Watts Calculator

Convert RF power between dBm and watts in either direction.

Decibel Gain Calculator

Calculate amplifier gain in decibels from voltage or power input and output levels.

EMC Filter Calculator

Design EMC/EMI power-line filters with CISPR 11/32 Class A and B limits. Calculate common-mode choke, differential-mode inductor, X/Y capacitor values, and attenuation curves.

Inductive Reactance Calculator

Calculate the inductive reactance (XL) of a coil from frequency and inductance.

LC Resonant Frequency Calculator

Calculate the resonant frequency of an LC tank circuit from its inductance and capacitance.

LED Resistor Calculator

Calculate the current-limiting series resistor for an LED from supply voltage, forward voltage, and current.

Motor Sizing Calculator

Size electric motors from mechanical load requirements for conveyors, pumps, fans, hoists, and compressors. Includes VFD current rating, service factor, and temperature/altitude derating.

Parallel Capacitance Calculator

Find the total capacitance of any number of capacitors wired in parallel.

Parallel Resistance Calculator

Find the equivalent resistance of any number of resistors wired in parallel.

Power Factor Calculator

Size capacitor banks for power factor correction with resonance checking, detuning reactor recommendations, and annual energy savings estimates with payback analysis.

RC Time Constant Calculator

Calculate the RC time constant and capacitor charging voltage over time for a resistor-capacitor circuit.

Series Capacitance Calculator

Find the equivalent capacitance of any number of capacitors wired in series.

SMPS Transformer Calculator

Design flyback and forward converter transformers with ferrite core selection, Steinmetz core loss, skin depth analysis, and turns calculations for switch-mode power supplies.

VFD Harmonics Calculator

Analyze VFD harmonic distortion for 6/12/18-pulse drives, check IEEE 519 compliance, calculate THDi and K-factor, and size passive filters for non-compliant installations.