Quick answer: Yellow, violet, red, gold is 4 and 7 followed by ×100: 47 × 100 = 4,700 Ω (4.7 kΩ) with ±5% tolerance, so between 4,465 and 4,935 Ω.
How it's calculated
On a 4-band resistor the first two bands are digits, the third is the multiplier (a power of ten) and the fourth is the tolerance. A 5-band resistor has three digit bands, which allows more precise values; a 6-band resistor adds a sixth band for the temperature coefficient.
Value = digits × multiplier. The tolerance gives the range the real resistance can fall in: value × (1 − tolerance) to value × (1 + tolerance).
The colours follow the international standard IEC 60062. Gold and silver are only used as multipliers (×0.1, ×0.01) or tolerances (±5%, ±10%), never as the first band, which tells you which end to start from. The precision tolerances follow the 2016 edition: orange ±0.05%, yellow ±0.02%, grey ±0.01%; some older charts list grey as ±0.05%.
Worked examples
- Yellow, violet, red, gold: 47 × 100 = 4,700 Ω ±5%
- Brown, black, black, red, brown (5 bands): 100 × 100 = 10,000 Ω = 10 kΩ ±1%
- Brown, black, orange, gold: 10 × 1,000 = 10 kΩ ±5%
Resistor colour code table (IEC 60062)
| Colour | Digit | Multiplier | Tolerance | Temp. coeff. (ppm/K) |
|---|---|---|---|---|
| Black | 0 | ×1 | — | 250 |
| Brown | 1 | ×10 | ±1% | 100 |
| Red | 2 | ×100 | ±2% | 50 |
| Orange | 3 | ×1,000 | ±0.05% | 15 |
| Yellow | 4 | ×10,000 | ±0.02% | 25 |
| Green | 5 | ×100,000 | ±0.5% | 20 |
| Blue | 6 | ×1,000,000 | ±0.25% | 10 |
| Violet | 7 | ×10,000,000 | ±0.1% | 5 |
| Grey | 8 | ×100,000,000 | ±0.01% | 1 |
| White | 9 | ×1,000,000,000 | — | — |
| Gold | — | ×0.1 | ±5% | — |
| Silver | — | ×0.01 | ±10% | — |
| None (no band) | — | — | ±20% | — |
Frequently asked questions
Which end do I read from?
Start at the end where the bands are closer together. The tolerance band (often gold or silver) is usually separated by a wider gap, and gold or silver is never the first band.
What does the tolerance mean?
How far the actual resistance may differ from the marked value. A 4.7 kΩ ±5% resistor measures anywhere from 4,465 to 4,935 Ω.
What is the 6th band?
The temperature coefficient: how much the resistance changes per degree, in parts per million per kelvin. Brown is 100 ppm/K, i.e. 0.01% per °C.
What value is yellow, violet, red, gold?
4.7 kΩ, give or take 5%. Yellow is 4, violet 7, red means add two zeros, and gold is the tolerance.
What is the E12 series?
The 12 standard values in each decade for 10% resistors: 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68 and 82, then the same again times 10, 100 and so on. 5% parts use E24, which fills in values between them.
How do I check a resistor's value?
Put a multimeter on ohms and measure it out of the circuit, or with at least one leg lifted. Anything connected alongside it will throw the reading off.