🎨 Resistor Color Code Calculator

Decode resistor color bands to find resistance values, or encode resistance values to color bands. Supports 4-band, 5-band, and 6-band resistors with tolerance and temperature coefficient.

Calculator Mode

Color Band Selection

Resistor Visualization & Results

Select colors or enter a value to see the resistor

Resistor Color Code Chart

HOW TO USE

Select the colors for each band on your resistor (4-band or 5-band). The calculator instantly shows the resistance value, tolerance, and acceptable range.

FORMULA USED

4-band: R = (d1×10 + d2) × 10^multiplier ± tolerance%
5-band: R = (d1×100 + d2×10 + d3) × 10^multiplier ± tolerance%

WORKED EXAMPLE

Brown-Black-Red-Gold (4-band): 1-0-×100-±5% = 1000 Ω (1kΩ) ±5%. Range: 950Ω to 1050Ω.

FREQUENTLY ASKED QUESTIONS

Q: What does each color band mean?

A: The first bands are digits (Black=0 to White=9), the next is the multiplier (10^n), and the last is tolerance (Gold=±5%, Silver=±10%).

Q: How do I read a 5-band resistor?

A: 5-band resistors have 3 digit bands, 1 multiplier band, and 1 tolerance band — allowing more precise values.

Q: What color is a 1kΩ resistor?

A: 1kΩ (4-band) is Brown-Black-Red-Gold. 1kΩ (5-band) is Brown-Black-Black-Brown-Brown.

Q: What if there is no tolerance band?

A: No tolerance band means ±20% tolerance. This is rare in modern resistors.