Resistor Color Code Calculator

Select the color bands on your resistor to find its value, tolerance, and temperature coefficient.

Resistance
1,000 Ω
±5% (950 - 1,050 Ω)
ColorDigitMultiplierTolerance
Black01 Ω
Brown110 Ω±1%
Red2100 Ω±2%
Orange31K Ω±0.05%
Yellow410K Ω±0.02%
Green5100K Ω±0.5%
Blue61M Ω±0.25%
Violet710M Ω±0.1%
Grey8100M Ω±0.01%
White91G Ω
Gold0.1 Ω±5%
Silver0.01 Ω±10%
Disclaimer: This tool is provided for general educational and entertainment purposes only. Results are estimates and should not be relied upon for any critical decision. Neither MayoCalc nor Cook Media Systems assumes any liability for consequences arising from the use of this tool. By using this site, you agree to our Terms of Service and Disclaimer.

How Resistor Color Codes Work

Resistors use colored bands to indicate their resistance value and tolerance. Most common resistors have 4 or 5 bands. For 4-band resistors: the first two bands are digits, the third band is the multiplier (power of 10), and the fourth band is the tolerance. For 5-band resistors: the first three bands are digits, the fourth is the multiplier, and the fifth is the tolerance.

How to Use This Calculator

Select the number of bands (4 or 5) and choose the color for each band from the dropdown. The calculator instantly shows the resistance value in ohms, kilohms, or megohms, along with the tolerance range (minimum and maximum actual resistance). You can also enter a resistance value and the calculator shows which color bands represent it.

Color Code Reference

The digit values are: Black=0, Brown=1, Red=2, Orange=3, Yellow=4, Green=5, Blue=6, Violet=7, Gray=8, White=9. Multiplier bands: Black=x1, Brown=x10, Red=x100, Orange=x1K, Yellow=x10K, Green=x100K, Blue=x1M. Tolerance bands: Brown=1%, Red=2%, Gold=5%, Silver=10%. The Ohm's Law Calculator uses the resistance value to compute voltage, current, and power.

Resistor FAQ

Which end do I read from?
Read from the end where the bands are closest together, or from the end opposite the tolerance band (gold or silver). The tolerance band usually has a slightly larger gap separating it from the other bands. If unsure, check both readings and see which produces a standard resistor value.

Resistor Selection Guide

Understanding resistor color codes is essential for circuit building and repair. The standard 4-band code uses the first two bands for significant digits, the third band as a multiplier, and the fourth band for tolerance (gold = 5%, silver = 10%, none = 20%). The 5-band code adds a third significant digit for precision resistors. Common tolerance values in modern electronics are 1% (brown band) and 5% (gold band). Preferred value series (E12, E24, E96) define standard resistance values available from manufacturers. The E12 series (10% tolerance) includes 12 values per decade: 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82. Understanding these series helps you select the closest available standard value to your calculated requirement.