Resistor Color Code Calculator
Decode a 4- or 5-band resistor into ohms with tolerance, or enter a resistance value and get the band colors back. Includes the min–max range.
How to use this calculator
1. Pick a direction
Use "Bands → Resistance" to read a physical resistor, or "Resistance → Bands" to find the colors for a value you already know.
2. Choose 4 or 5 bands
Hold the resistor with the tolerance band (often gold or silver) on the right. Count the bands and select 4 or 5 to match.
3. Set each band's color
Read left to right and pick the color for each digit band, the multiplier, and the tolerance. The result updates as you go.
4. Check the range
The tolerance gives a min–max window. A 1 kΩ ±5% part can legitimately measure anywhere from 950 Ω to 1050 Ω. Pair this with Ohm's Law for circuit design.
About resistor color codes
Digits and multiplier
Digit colors run black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9. The multiplier band raises the significant figures by a power of ten; gold means ×0.1 and silver ×0.01.
Tolerance
The tolerance band shows how far the real value may stray: brown ±1%, red ±2%, green ±0.5%, blue ±0.25%, violet ±0.1%, gold ±5%, silver ±10%, and no band ±20%.
4-band vs. 5-band
A 4-band resistor uses two significant digits; a 5-band adds a third for tighter, more precise values. Otherwise the multiplier and tolerance bands work the same way.