OneTool

Resistor Color Code Calculator

Colors ↔ resistance for common through-hole resistors.

Bands
Mode
1st digit
2nd digit
Multiplier
Tolerance

Resistance

1 kΩ ±5%

What is this tool?

Through-hole resistors encode value and tolerance with colored bands. Four-band parts use two significant digits, a multiplier, and tolerance; five-band parts add a third significant digit. This tool works both directions with visual color swatches.

How to use it

  1. Choose 4-band or 5-band mode.
  2. Either select band colors to read resistance, or enter ohms to get suggested bands.
  3. Confirm tolerance and measure with a meter when precision matters.