🔌 Electronics

Resistor decoders, LED calculators, capacitor tools and more for electronics hobbyists

Decode 4-band and 5-band resistor color codes instantly. Free visual resistor calculator.

Calculate the resistor needed for an LED circuit. Enter supply voltage, LED forward voltage and current.

Decode 3-digit ceramic capacitor codes (e.g. 104 = 100nF). Instant conversion to pF, nF, µF.

Calculate output voltage from a resistive voltage divider. Enter Vin, R1, R2.

Calculate frequency, duty cycle, and timing for 555 timer circuits in astable and monostable modes.

Calculate minimum PCB copper trace width for a given current, using IPC-2221 standards.

AWG wire gauge reference table with diameter, area, resistance, and max current ratings.

Calculate the time constant, charge time, and discharge curves for RC circuits.

Decode 4-band inductor color codes to inductance in µH and mH.

Calculate voltage, current, resistance, or power from any two known values.

Decode 3-digit, 4-digit, and EIA-96 SMD resistor codes to resistance values.