Resistor Color Code Calculator
Decode color bands into ohms or turn a resistance back into color bands, with a realistic resistor drawing
Resistor color code chart
| Color | Digit | Multiplier | Tolerance | ppm/K |
|---|---|---|---|---|
| Black | 0 | ×1 | — | 250 |
| Brown | 1 | ×10 | ±1% | 100 |
| Red | 2 | ×100 | ±2% | 50 |
| Orange | 3 | ×1k | — | 15 |
| Yellow | 4 | ×10k | — | 25 |
| Green | 5 | ×100k | ±0.5% | 20 |
| Blue | 6 | ×1M | ±0.25% | 10 |
| Violet | 7 | ×10M | ±0.1% | 5 |
| Gray | 8 | ×100M | ±0.05% | 1 |
| White | 9 | ×1G | — | — |
| Gold | — | ×0.1 | ±5% | — |
| Silver | — | ×0.01 | ±10% | — |
About this tool
The resistor color code calculator turns the colored bands printed on a resistor into a resistance value, and works the other way too: type an ohm value and it shows the matching color bands. It supports 4-band, 5-band, and 6-band resistors, reads the tolerance band, and on 6-band parts also reads the temperature coefficient. A realistic resistor drawing updates as you pick colors, and a full color code chart is included so you can learn the system. It is built for makers, electronics students, and hobbyists who need to read a resistor without reaching for a datasheet.
How to use
- 1 Pick a mode: decode color bands into a value, or encode a value into bands.
- 2 Choose the number of bands on your resistor: 4, 5, or 6.
- 3 Select each band color from the dropdowns, or type a resistance like 4.7k in encode mode.
- 4 Read the resistance, tolerance, range, and (for 6 bands) temperature coefficient, and check the live drawing.
How it works
Each color stands for a number: black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, gray 8, white 9. On a 4-band resistor the first two bands are significant digits, the third is a power-of-ten multiplier, and the fourth is the tolerance. A 5-band resistor adds a third significant digit before the multiplier for more precision, and a 6-band resistor adds a final band for the temperature coefficient in ppm/K. The multiplier band uses the same colors plus gold for 0.1 and silver for 0.01, so small resistances are possible. The tolerance band is usually gold (±5%), silver (±10%), brown (±1%), or red (±2%). For example, yellow-violet-red-gold reads 4 and 7 to make 47, times 100 = 4700 ohms, with ±5% tolerance, which is the common 4.7 kΩ resistor. Reading the other way, 4700 ohms with ±5% gives exactly those four bands.
Frequently asked questions
Which end of the resistor do I read first?
Read from the band closest to an edge. The tolerance band (often gold or silver) is usually slightly separated and sits at the far end, so start from the opposite side where the digit bands are grouped together.
What is the difference between 4, 5, and 6 band resistors?
A 4-band resistor has two significant digits, a multiplier, and a tolerance. A 5-band resistor adds a third significant digit for tighter precision, common in 1% parts. A 6-band resistor adds one more band giving the temperature coefficient in ppm/K, used in high-precision designs.
What do the gold and silver bands mean?
As a multiplier, gold means ×0.1 and silver means ×0.01, used for resistances below 10 ohms. As a tolerance band, gold means ±5% and silver means ±10%. Their position on the resistor tells you which role they play.
Why does my value not match a standard resistor?
Real resistors come in standard E-series values such as 4.7 kΩ or 10 kΩ. This calculator shows the exact bands for whatever value you enter; if it is not a stock value you would pick the nearest E-series resistor or combine several to reach it.
Related tools and uses
For other engineering math, try the scientific notation converter for very large or small values, the number base converter for binary and hex, and the formula solver for Ohm's law and power calculations.
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