How to Read a Resistor Color Code (Bands to Ohms)

A resistor is too small to print a number on, so its value is written in colored bands — a code that looks cryptic until you know the trick. Once you do, you can read any resistor at a glance: the first bands are digits, the next multiplies them, and the last tells you how precise it is.

The color-to-number table

The heart of it is a single mapping from color to digit, easy to remember once and use forever:

Color	Digit	As multiplier
Black	0	×1
Brown	1	×10
Red	2	×100
Orange	3	×1 k
Yellow	4	×10 k
Green	5	×100 k
Blue	6	×1 M
Violet	7	×10 M
Grey	8	—
White	9	—

Plus two fractional multipliers for small resistors: Gold ×0.1 and Silver ×0.01.

Reading a 4-band resistor

The classic resistor has four bands. Reading from the grouped end:

1. First band — the first digit.
2. Second band — the second digit.
3. Third band — the multiplier (how many zeros to add).
4. Fourth band — the tolerance.

So Brown-Black-Red-Gold is: 1 (brown), 0 (black), ×100 (red) → 1000 Ω = 1 kΩ, at ±5% (gold). A 1 kΩ ±5% resistor is guaranteed to fall between 950 Ω and 1,050 Ω.

Which end do I start from?

This is the one thing beginners get wrong. Read from the end where the bands are grouped closest together; the tolerance band is slightly separated and comes last. If you can’t tell, the tolerance band is usually the odd one out — a gold or silver band, or the one with a visible gap before it. Read a resistor backwards and you’ll get a wildly different (and wrong) value, so it’s worth checking.

5-band and 6-band resistors

Precision resistors add bands. A 5-band resistor has three digit bands before the multiplier, giving an extra significant figure (so a value like 4.7 kΩ can be marked exactly), usually at a tight ±1% tolerance. A 6-band resistor adds one more: a temperature coefficient, in parts per million per °C, telling you how much the resistance drifts as it heats up — important for precision analog and measurement circuits.

Just read it for me

Memorising the code is handy, but you don’t have to. The resistor color code calculator lets you pick each band’s color from a menu and shows the resistance, tolerance and range instantly — with a live picture of the resistor so you can match it to the part in your hand. It handles 4, 5 and 6-band resistors, and like every LazyTools tool it runs entirely in your browser. Building a circuit around it? The LED resistor calculator sizes the resistor an LED needs, and the capacitor code calculator decodes the matching capacitor markings.

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Values follow the IEC 60062 resistor color code. Tolerance gives the guaranteed range around the nominal value; the ultra-tight tolerance-band colors (used on precision parts) vary slightly between references, so check the datasheet for critical applications.