4-band: yellow, violet, red, gold
- Input
- Bands = yellow, violet, red, gold
- Working
- Digits 4 and 7 make 47; the red multiplier is ×100, so 47 × 100 = 4,700 Ω = 4.7 kΩ. The gold band sets the tolerance at ±5%.
- Result
- 4.7 kΩ ±5%
Resistor Colour Code Calculator
Read any 4-, 5- or 6-band resistor: pick the band colours and get the resistance, tolerance and temperature coefficient, with a visual resistor that updates. Runs entirely in your browser — your numbers never leave this device.
Band count
Resistance
4.7 kΩ
±5% tolerance
- Resistance
- 4.7 kΩ
- Ohms
- 4700 Ω
- Tolerance
- ±5%
- Tempco
- —
How it works
Value = digits × multiplier — 4-band: 2 digits; 5-/6-band: 3 digits | e.g. yellow (4), violet (7), red (×100) = 47 × 100 = 4,700 Ω = 4.7 kΩ
| Colour | Digit | Multiplier | Tolerance | Tempco (ppm/K) |
|---|---|---|---|---|
| Black | 0 | ×1 | — | — |
| Brown | 1 | ×10 | ±1% | 100 |
| Red | 2 | ×100 | ±2% | 50 |
| Orange | 3 | ×1,000 | — | 15 |
| Yellow | 4 | ×10,000 | — | 25 |
| Green | 5 | ×100,000 | ±0.5% | — |
| Blue | 6 | ×1,000,000 | ±0.25% | 10 |
| Violet | 7 | ×10,000,000 | ±0.1% | 5 |
| Grey | 8 | ×100,000,000 | ±0.05% | — |
| White | 9 | ×1,000,000,000 | — | — |
| Gold | — | ×0.1 | ±5% | — |
| Silver | — | ×0.01 | ±10% | — |
| None (no band) | — | — | ±20% | — |
Through-hole resistors print their value as coloured bands because numbers would be too small to read. Each colour stands for a digit — black 0 through white 9, in rainbow order from brown 1 to violet 7 — and the bands are read in roles: the first two bands (three on 5- and 6-band parts) are the significant digits, the next band is the multiplier, a power of ten from silver (×0.01) to white (×10⁹), and the remaining band is the tolerance. Gold and silver never appear as digits; they exist for the fractional multipliers and the looser tolerances, ±5% and ±10%. A 6-band part adds a temperature coefficient in ppm/K — how many parts per million the value drifts per degree — with brown the coarsest at 100 and violet the finest at 5.
Orientation is the classic trap: read from the end where the bands are grouped closest together, with the tolerance band — often gold or silver, and set slightly apart — last. This calculator draws the resistor as you pick, so the visual order can be matched against the part in your hand before trusting the number. The E12 series row in the LED Resistor Calculator's method is the companion idea: preferred values repeat every decade in the pattern 1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2 — which is why a decoded 4.7 kΩ is a standard part and a decoded 4.8 kΩ usually means a band was misread.
Worked examples
5-band: brown, black, black, red, brown
- Input
- Bands = brown, black, black, red, brown
- Working
- Three digits 1, 0, 0 make 100; the red multiplier is ×100, so 100 × 100 = 10,000 Ω = 10 kΩ. The final brown band is ±1% — a precision part.
- Result
- 10 kΩ ±1%
6-band: yellow, violet, black, red, brown, brown
- Input
- Bands = yellow, violet, black, red, brown, brown
- Working
- Digits 4, 7, 0 make 470; ×100 gives 47,000 Ω = 47 kΩ. Brown tolerance is ±1%, and the sixth brown band adds a temperature coefficient of 100 ppm/K.
- Result
- 47 kΩ ±1% · 100 ppm/K
Frequently asked questions
Which end do I read a resistor from?
The end where the bands are bunched closest to the edge — the tolerance band (usually gold, silver, or a precision colour) sits apart at the other end and is read last. If the spacing is ambiguous, use the value as a check: a genuine decoded value is almost always a standard E12 or E24 figure like 4.7 kΩ, while reading backwards usually produces a non-standard one.
What is the difference between 4-band and 5-band resistors?
Precision. A 4-band part carries two significant digits and tolerances of ±5%, ±10% or ±20%; a 5-band part carries three significant digits and tolerances of ±1% or tighter, so values like 49.9 kΩ that two digits cannot express can be marked. The 6-band part adds the temperature-coefficient band on top of the 5-band layout.
What does the temperature coefficient mean?
How much the resistance drifts with temperature, in parts per million per kelvin. A 47 kΩ resistor at 100 ppm/K changes by 47,000 × 100 ÷ 1,000,000 = 4.7 Ω per degree — irrelevant in a toy, decisive in a measurement bridge. Only 6-band resistors mark it; the finest marked value here is violet at 5 ppm/K.
Why can the first band never be black?
Because black is digit 0, and a leading zero would make the marked value ambiguous — a part is never specified as '047 × …'. If the band nearest the end looks black, you are most likely reading the resistor from the wrong end, or that band is the multiplier of a part held the other way round.
My resistor has only 3 bands. How do I read it?
As a 4-band part with the tolerance band missing: two digits and a multiplier, with the absent tolerance band meaning ±20% by convention. Enter the three colours as the first three bands of the 4-band mode here and read the value ignoring the tolerance line.
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