Resistor color code — how to read the bands (220 Ω, 1 kΩ, 10 kΩ)

#The short answer

On a common 4-band resistor:

1. Band 1 = first digit
2. Band 2 = second digit
3. Band 3 = multiplier (how many zeros to add)
4. Band 4 = tolerance (how exact it is) — usually gold (±5 %)

So red, red, brown, gold = 2, 2, one zero = 220 Ω, ±5 %.

#The color code table

The digits follow the rainbow, with black and brown in front and grey and white behind. A popular memory line for 0 to 9: "Better Be Right Or Your Great Big Venture Goes Wrong" — black, brown, red, orange, yellow, green, blue, violet, grey, white.

#Which end do I start from?

Hold the resistor so that the gold or silver band is on the right. That band is the tolerance, so you read from the other end. The tolerance band also usually has a slightly bigger gap before it. If there is no gold or silver band, start from the end where the bands sit closest to the edge.

#Worked example 1: 220 Ω (for LEDs)

2, 2, add one zero → 220 Ω. This is the resistor in front of almost every LED on this site, from Blink to the RGB LED. With ±5 %, the real value can be anywhere from 209 Ω to 231 Ω — no problem at all.

#Worked example 2: 1 kΩ

1, 0, add two zeros → 1 000 Ω = 1 kΩ. Our DC motor project uses a 1 kΩ resistor between pin 6 and the transistor's base.

#Worked example 3: 10 kΩ

1, 0, add three zeros → 10 000 Ω = 10 kΩ. This is the pull-down in the push button project and the partner of the light sensor in the night light.

Play in 3DRun the code · press the parts · turn it around

#5-band resistors

Precision resistors (often with a blue body) have three digit bands, then the multiplier, then the tolerance — usually brown (±1 %).

For 220 Ω on a 5-band resistor: 2, 2, 0, then black (no more zeros) → 220 Ω.

#Quick ways to check

• A multimeter on the Ω setting gives the real value in a second. Don't hold both legs with your fingers — your body adds resistance.
• Keep them sorted. Tape a strip of each value to a card and write the value on it.
• In our 3D lab you can set each resistor's resistance on the Build bench — handy for seeing how 220 Ω, 1 kΩ and 10 kΩ change an LED's brightness.

#Check yourself

#Questions people ask

#How do you read a resistor color code?

Put the gold or silver band on the right. The first two bands are digits, the third tells you how many zeros to add, and the last is the tolerance. Red-red-brown is 2, 2 and one zero: 220 Ω.

#What is the color code for a 220 ohm resistor?

On a 4-band resistor: red, red, brown, gold. On a 5-band resistor: red, red, black, black, brown.

#What color is a 10k resistor?

Brown, black, orange, gold on a 4-band resistor; brown, black, black, red, brown on a 5-band one.

#Does it matter which way round a resistor goes?

No. A resistor works the same in both directions, so you can push it into the breadboard either way. The direction only matters for reading its bands.

Last updated 2026-10-29