Electronics

Calculators that draw the circuit for you. Change a value and watch the schematic, waveform or plot update live. Free, no sign-up, works offline once loaded.

🌈 Resistor Color Code 🔋 Capacitor Code ⚡ Ohm's Law 💡 LED Resistor ➗ Voltage Divider ⏱️ 555 Timer

All electronics tools

Resistor Color Code Read 4, 5 and 6 band resistors or find the colours for any value, plus SMD codes (3-digit, 4-digit, EIA-96).

Capacitor Code & Converter Decode ceramic capacitor markings like 104K or 2A473J, convert pF/nF/µF, and read X7R/C0G dielectric codes.

Ohm's Law Calculator Enter any two of voltage, current, resistance and power to get the rest, with a live circuit and the formula wheel.

LED Resistor Calculator The right series resistor for one LED or a string, with the nearest standard value, power rating and a glowing circuit.

Voltage Divider Calculator Output voltage for two resistors (with an optional load), or the best standard resistor pair for a target voltage.

555 Timer Calculator Astable frequency and duty cycle or monostable pulse length, with the circuit and an animated output waveform.

RC / RL / LC Filter Calculator Cutoff and resonant frequencies for RC, RL and RLC filters, drawn as a Bode plot of gain and phase.

PCB Trace Width Calculator IPC-2221 trace width for a given current and temperature rise, with resistance, voltage drop and power loss.

AWG Wire Gauge & Voltage Drop AWG sizes in mm and mm², resistance per length, voltage drop for your cable run, and true-size wire drawings.

Interactive Pinouts Clickable pin maps for the ESP32-S3-DevKitC-1, Raspberry Pi 40-pin header and Arduino Uno, filtered by I²C, SPI, UART, ADC and more.

Open-source hardware projects from ICBizLabs

The team behind kilaz.com also builds and publishes these:

ESP32-DIV (Kilaz Edition)

Wireless security research firmware for ESP32-DIV V2 boards on the ESP32-S3, with 87 features and a one-click browser installer.

View on GitHub →

MatrixWeatherClock

64×32 HUB75 LED clock on an ESP32-S3: local weather, NWS emergency alerts, lightning strikes and alarms, with self-updating firmware.

View on GitHub →

NyxScope

Free SDR scanner for Windows: ADS-B, AIS, P25, DMR, pagers and weather sensors with an RTL-SDR dongle.

Get NyxScope →

Into radio too? See the Radio & Satellite tools: antenna and RF calculators, satellite tracking and live propagation maps.