Resistor colour codes explained: how to read 4, 5 and 6-band resistors

Resistor colour bands encode the value directly: the first bands are digits, the next is a multiplier, and the last is the tolerance. Yellow–violet–red–gold reads as 4, 7, ×100 — 4.7 kΩ at ±5%. Ten colours cover the digits 0 to 9, and once the sequence is familiar you can price up a mixed bag of resistors faster than you can type values into a meter.

This guide gives the full colour chart, worked examples for 4-band and 5-band parts, the orientation trap that catches everyone at least once, the reason resistors come in strange values like 4.7 k and 68 k in the first place, and the marking systems used on SMD parts where there's no room for stripes at all.

Resistor colour code chart

If a mnemonic helps the digit sequence stick: Better Be Right Or Your Great Big Values Go Wrong — black, brown, red, orange, yellow, green, blue, violet, grey, white.

How do you read a 4-band resistor?

Four bands decode as digit, digit, multiplier, tolerance. Two examples cover the pattern:

• Yellow, violet, red, gold: 4 and 7 make 47, red multiplies by 100 → 4,700 Ω = 4.7 kΩ, gold gives ±5%
• Brown, black, orange, gold: 1 and 0 make 10, orange multiplies by 1,000 → 10 kΩ ±5%

The gold and silver multipliers handle sub-10 Ω values: red–red–gold reads 22 × 0.1 = 2.2 Ω, the kind of value found in current-sense positions and covered at the low-ohmic end of the range.

How do you read 5-band and 6-band resistors?

Precision parts add a third digit band: digit, digit, digit, multiplier, tolerance. That extra digit is what lets a ±1% metal film resistor express values like 4.99 k that the 4-band system simply can't write. The side-effect is that the same value looks different in each format — 10 kΩ is brown–black–orange in 4-band but brown–black–black–red in 5-band, because the digits are now 1–0–0 with a ×100 multiplier. Misreading a 5-band part as 4-band is the single most common decoding error.

A sixth band, where present, states the temperature coefficient — how much the value drifts per degree — with brown marking the common 100 ppm/°C grade and red 50 ppm/°C. For most work it can be ignored; for precision analogue design it's the reason the band exists.

Which end do you start reading from?

Three rules settle orientation. The tolerance band usually sits separated by a wider gap from the digit group — start from the tightly grouped end. Gold and silver can never be first-position digits, so if a gold band leads your reading, you're holding it backwards. And on 5-band parts where both ends look plausible, the deciding vote goes to the meter: a multimeter or component tester takes seconds and settles brown-versus-red arguments that poor light and faded bands can't. Colour tells you the nominal value; the meter tells you the truth — and out of circuit, always, since surrounding components skew in-circuit readings.

Why do resistors come in odd values like 4.7 k?

The catalogue values look arbitrary — 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82 — but they're precisely engineered. These are the E12 preferred numbers, spaced logarithmically so that each value's ±10% tolerance band just meets its neighbour's: any resistance you could ask for is within tolerance of some standard part, with no wasteful overlap. The E24 series halves the spacing for ±5% parts, and E96 populates the gaps for ±1% precision work. So 47 k exists instead of 50 k not by accident but because 47 sits on the logarithmic grid — and once you know the E12 dozen, you know what every resistor kit on earth contains.

How are SMD resistors marked?

Surface-mount parts trade stripes for printed codes. The 3-digit system reads like a compressed colour code: two digits then a power-of-ten multiplier, so 472 is 47 × 10² = 4.7 kΩ, and 100 is 10 Ω, not 100 Ω — a trap with real consequences. Four-digit codes work the same with three significant digits (4702 = 47 kΩ) and mark ±1% parts. An R stands in for a decimal point: 4R7 is 4.7 Ω. The smallest packages use the EIA-96 system — two digits looking up a value table plus a multiplier letter — or carry no marking at all, in which case the reel label and a meter are the only authorities. Codes and sizes go together across the 0603, 0805 and 1206 ranges.

One marking deserves its own mention: a resistor printed simply "0", or a through-hole part with a single black band, is a zero-ohm resistor — a wire link in a resistor's costume, existing so pick-and-place machines can fit jumpers like any other component.

Featured resistors

Frequently asked questions

What value is yellow, violet, red, gold?

4.7 kΩ at ±5%. Yellow is 4, violet is 7, red multiplies by 100 to give 4,700 Ω, and gold sets the tolerance at ±5%.

What order do resistor colour bands go in?

Digits first, then multiplier, then tolerance — two digits on 4-band parts, three on 5-band. Start from the end where bands are grouped closest together; the tolerance band typically sits apart with a wider gap.

What does a gold band mean?

In the last position, ±5% tolerance — its most common meaning. As a multiplier band it means ×0.1, used for values below 10 Ω. Gold is never a digit, which is a handy orientation check.

Why is there no 50 kΩ resistor?

Standard values follow the logarithmic E-series, spaced so adjacent values' tolerance bands meet without gaps or waste. 47 k sits on that grid; 50 k doesn't. The E12 dozen — 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82 — repeats in every decade.

What is a zero-ohm resistor for?

It's a machine-placeable wire link — marked "0" or with a single black band — used to bridge tracks, select circuit options and cross traces on single-sided boards using the same automated assembly as every other component.

How do I read an SMD resistor marked 472?

Two significant digits and a multiplier: 47 followed by two zeros — 4.7 kΩ. Note the trap: 100 means 10 Ω (10 with no zeros), and an R marks a decimal point, so 4R7 is 4.7 Ω.

Stock the values that matter

From E12 starter kits for the classroom to ±1% metal film and SMD reels for production, the standard values are all here — with the meters to prove them.