Resistor Colour Code Calculator
Use the GeekPCBs resistor colour code calculator to work out resistor values from 4-band, 5-band, and 6-band colour codes. Select each resistor band colour to calculate the resistance value, multiplier, tolerance, and full colour code. This tool is useful for arcade PCB repairs, pinball board repairs, power supply work, display boards, and general electronics troubleshooting.
Resistor Calculator
Select the resistor band colours below to calculate resistance and tolerance.
Band 1
Band 2
Band 3
Band 3
Band 4
Resistance
Tolerance
Colour Code
| Colour | Digit | Multiplier | Tolerance |
|---|---|---|---|
| Black | 0 | ×1 | — |
| Brown | 1 | ×10 | ±1% |
| Red | 2 | ×100 | ±2% |
| Orange | 3 | ×1k | — |
| Yellow | 4 | ×10k | — |
| Green | 5 | ×100k | ±0.5% |
| Blue | 6 | ×1M | ±0.25% |
| Violet | 7 | ×10M | ±0.1% |
| Grey | 8 | ×100M | ±0.05% |
| White | 9 | ×1G | — |
| Gold | — | ×0.1 | ±5% |
| Silver | — | ×0.01 | ±10% |
| No Band | — | — | ±20% |
How to Use the Resistor Calculator
Choose the resistor type, then select each colour band from left to right. For a standard 4-band resistor, the first two bands are the digits, the third band is the multiplier, and the fourth band is the tolerance. For example, a resistor with brown, black, red, and gold bands is 1 kΩ with ±5% tolerance.
Resistor Colour Code Example
A 4-band resistor with brown, black, red, and gold bands is calculated like this:
Brown = 1
Black = 0
Red = ×100 multiplier
Gold = ±5% tolerance
The final value is 1 kΩ ±5%.
Resistor Colour Code FAQ
What does the gold band mean on a resistor?
The gold band usually means the resistor has a tolerance of ±5%.
What does the silver band mean on a resistor?
The silver band usually means the resistor has a tolerance of ±10%.
Which end of the resistor do I read first?
Read the resistor from the end where the colour bands are grouped closest together. The tolerance band is usually spaced slightly apart at the end.
What is a 4-band resistor?
A 4-band resistor uses two digit bands, one multiplier band, and one tolerance band.