Resistor Color Code: How to Read the Bands
A reference for decoding the digit, multiplier, tolerance, and temperature-coefficient bands on axial resistors.
What Is a Resistor Color Code?
Through-hole axial resistors are too small to print a resistance value and tolerance on legibly, so manufacturers mark them with a sequence of colored bands instead. Each color stands for a digit, a power-of-ten multiplier, or a tolerance percentage, and the standard — IEC 60062 — is universal, so a resistor made by any manufacturer, in any country, reads the same way. Bands also have a practical advantage over printed text: they are readable from any angle the part happens to be lying in on a bench or in a bin.
Surface-mount (SMD) resistors use a different convention — a short printed numeric code on the chip's top face — because they are large enough to print on and small color bands would be impossible to distinguish at that size. This guide covers the banded code used on axial (leaded) resistors only.
Which End Do You Read First?
The bands are grouped into two clusters with a gap between them, and that gap is the key to orientation: the digit and multiplier bands sit close together at one end, while the tolerance band sits alone, noticeably farther from its neighbors, closer to the other lead. The tolerance band is also almost always gold or silver — colors that never appear as a significant digit — which makes it easy to spot even without measuring the spacing by eye.
Once you have found the tolerance band, orient the resistor with that band on your right and read the remaining bands from left to right: digits first, then the multiplier. If a resistor has no gold or silver band at all (a rare ±20%, unbanded-tolerance part), fall back on the gap alone — the tolerance-side gap is still wider than the spacing between the digit bands. When the orientation is still genuinely ambiguous, try reading it both ways and keep whichever result lands on a real standard value; a multimeter reading resolves any remaining doubt in seconds.
4-Band Resistors: 2 Significant Digits
The 4-band code is the one you will see on the vast majority of general-purpose resistors — the common ±5% and ±10% parts drawn from the E12 and E24 standard-value series. It packs the value into four bands: two significant digits, a multiplier, and a tolerance.
R = (10 × digit1 + digit2) × multiplier
For example, a resistor banded Yellow-Violet-Red-Gold reads as digits 4 and 7, multiplier ×100, tolerance ±5% — that is 47 × 100 = 4,700 Ω, or 4.7 kΩ ±5%. A resistor banded Brown-Black-Orange-Gold reads as digits 1 and 0, multiplier ×1,000 — 10 × 1,000 = 10,000 Ω, or 10 kΩ ±5%.
5-Band and 6-Band Resistors: 3 Significant Digits
Once a resistor is held to a tighter tolerance — the ±1%, ±0.5%, ±0.25%, and ±0.1% parts drawn from the E48, E96, and E192 series — two significant digits are no longer enough to express the value precisely, since those series pack far more values into each decade. The 5-band code adds a third significant digit to cover this:
R = (100 × digit1 + 10 × digit2 + digit3) × multiplier
For example, Brown-Black-Black-Brown-Brown reads as digits 1, 0, 0, multiplier ×10, tolerance ±1% — 100 × 10 = 1,000 Ω, or 1 kΩ ±1%.
A 6-band resistor is a 5-band resistor with one more band added after the tolerance: an optional temperature coefficient (TCR), given in parts per million per degree Celsius (ppm/°C). It bounds how much the resistance drifts as temperature moves away from 25°C — relevant in precision references, current-sense resistors, and any circuit that has to hold its accuracy across a wide operating-temperature range, but usually irrelevant for general-purpose work. Brown-Black-Black-Brown-Brown-Brown is the same 1 kΩ ±1% resistor as above, with a 100 ppm/°C temperature coefficient added.
Color Code Reference Tables
Digit, multiplier, and tolerance values share the same color scale — Black through White for the digits 0–9, with Gold and Silver reserved for the fractional multipliers and the two most common wide tolerances.
| Color | Digit | Multiplier | Tolerance |
|---|---|---|---|
| Black | 0 | ×1 | — |
| Brown | 1 | ×10 | ±1% |
| Red | 2 | ×100 | ±2% |
| Orange | 3 | ×1,000 | — |
| Yellow | 4 | ×10,000 | — |
| Green | 5 | ×100,000 | — |
| Blue | 6 | ×1,000,000 | — |
| Violet | 7 | ×10,000,000 | — |
| Grey | 8 | ×100,000,000 | — |
| White | 9 | ×1,000,000,000 | — |
| Gold | — | ×0.1 | ±5% |
| Silver | — | ×0.01 | ±10% |
| None (no band) | — | — | ±20% |
The optional 6th band on a 6-band resistor uses a smaller subset of colors for the temperature coefficient:
| Color | Temperature Coefficient |
|---|---|
| Brown | 100 ppm/°C |
| Red | 50 ppm/°C |
| Orange | 15 ppm/°C |
| Yellow | 25 ppm/°C |
Quick Tips for Reading Bands in Practice
- Gold and silver are never digits. If a band you expected to be a significant digit turns out gold or silver, you have started from the wrong end — flip the resistor and read it from the other side.
- Brown, red, and orange are easy to confuse under poor or yellow-tinted lighting. Check the value against a multimeter, or against the standard-value tables, if two colors look similar.
- Count the bands before you start reading. A 4th band that is gold or silver is tolerance, not a multiplier — miscounting the bands is the single most common source of a misread value.
- When in doubt, measure it. A color code tells you the marked value; a multimeter tells you the actual value, and the two only have to agree within the marked tolerance.
Related Guides
Standard Resistor Values — E6 to E192 Reference Tables
Once you decode a band into digits and a multiplier, check it against the full E6–E192 tables to confirm it lands on a real standard value.
Resistor Tolerance and How It Stacks in a Network
The tolerance band tells you the ± percentage a single part can drift — this guide covers what that bound means and how it compounds once resistors are combined.
Frequently Asked Questions
- Which end of the resistor do I start reading the color bands from?
- Start from the end farthest from the tolerance band. The tolerance band is almost always gold or silver and sits by itself with a visible gap before it, while the digit and multiplier bands are grouped tightly together at the opposite end. Hold the resistor with that gap on your right and read the remaining bands left to right.
- What's the difference between 4-band, 5-band, and 6-band color codes?
- A 4-band code uses 2 significant digits, a multiplier, and a tolerance band, and is standard on general-purpose E12/E24 resistors (5% or 10% tolerance). A 5-band code adds a third significant digit for the tighter tolerances used on E48/E96/E192 parts (1%, 0.5%, 0.25%, 0.1%). A 6-band code is a 5-band code plus an optional temperature-coefficient band that specifies how much the resistance drifts per degree Celsius.
- What does it mean if a resistor's color bands are gold or silver but aren't the last band?
- Gold and silver only ever appear as a multiplier (×0.1 and ×0.01) or as a tolerance (±5% and ±10%) — never as a significant digit. If you see gold or silver anywhere other than the last one or two bands, you have almost certainly picked the wrong end to start reading from; flip the resistor around and read it from the other side.
- What tolerance does a resistor have if it has no tolerance band at all?
- No tolerance band at all (just 3 bands: two digits and a multiplier) means ±20% tolerance. This is rare on modern parts — nearly everything manufactured today carries at least a gold (±5%) or brown (±1%) band — but it does turn up on older stock.
- What does the temperature coefficient band actually affect?
- The temperature coefficient (TCR), given in ppm/°C on the optional 6th band, bounds how far the resistance drifts as the part heats up or cools down relative to 25°C. A 100 ppm/°C resistor changes by 0.01% of its value per degree, which is negligible for most circuits but matters in precision references, sense resistors, or anything operating across a wide temperature range.