Resistor Calculator & SMD

Resistor Calculator for quick, accurate resistor calculations. Decode a resistor color code (resistor colour code) for 3 band, 4 band, and 5 band resistors, and convert an SMD resistor code into the correct resistance value.

Use it during design, study, repairs, or breadboard prototyping to verify resistor values and common circuit results without doing the math by hand.

Tools included:

- 4 band / 5 band resistor color code calculator.

- SMD resistor value calculator (SMD resistor code).

- Resistors in series calculator (equivalent resistance).

- Resistors in parallel calculator (equivalent resistance).

- LED resistor calculator (pick a resistor for an LED circuit).

- Voltage divider calculator (output voltage).

- Resistivity calculator.

Designed to be simple and fast: enter the band colors or SMD marking, then get the resistance value in ohms (Ω) at a glance.

Ideal for electronics students, hobbyists, and engineers.