Resistor Color Picker & Calculator

Pick 4/5/6 bands to decode resistance, tolerance, and tempco. Includes Show Work and share links.

How to Use

  1. Select band count (4, 5, or 6).
  2. Pick colors for each band (digits, multiplier, tolerance, optional tempco).
  3. Read the decoded value (Ω), tolerance (%), and tempco (ppm/°C) below.
  4. Open “Show Work” for the exact math used.
Resistor Preview
Band order is left-to-right. Use the band count to match your part.
Ω
—
Tol
—
Tempco
—
Bands
4
Tip: 4-band = 2 digits + multiplier + tolerance. 5/6-band = 3 digits + multiplier + tolerance (+ tempco).
Band Picker
Choose the color for each band. Band roles update automatically with band count.
First significant digit (0–9)
Second significant digit (0–9)
For 5/6-band: third digit. For 4-band: multiplier.
For 5/6-band: multiplier. For 4-band: tolerance.
Tolerance band (e.g., Gold ±5%, Brown ±1%)
Temperature coefficient (ppm/°C), used on some precision resistors
Show Work (step-by-step)
—
Work is shown using the standard resistor color-code rules (digits + multiplier + tolerance + tempco).

Reference

Standard decoding: Value = (significant digits) × multiplier with tolerance as ±%. For 6-band, the last band is tempco in ppm/°C.

Note: Some resistors have printed values instead of bands (especially SMD). This tool targets banded through-hole resistors.

FAQ

What’s the difference between 4 and 5 bands?

4-band uses 2 digits + multiplier + tolerance. 5-band uses 3 digits + multiplier + tolerance for more precision.

What does the 6th band mean?

The 6th band is usually tempco (temperature coefficient), expressed as ppm/°C.

How do I know which side to read from?

Tolerance/tempco bands (gold/silver/brown/blue, etc.) are often spaced slightly from the others. Use “Flip Read Direction” if your resistor’s layout is reversed.

Tool Info

Last updated:

Updates may include band options, edge-case handling, and UI improvements.