What is my resistor value?
Pick the number of bands and the colour of each one. The resistor calculator reads the IEC 60062 colour code and gives the resistance and its range.
- Resistance
- 4.7 kΩ
The bands mean 4.7 kΩ ± 5%: from 4.465 kΩ to 4.935 kΩ.
- Resistance in ohms
- 4,700
- Tolerance
- 5%
- Lowest resistance
- 4.465 kΩ
- Highest resistance
- 4.935 kΩ
- Colour code
- 47 × 10^2
Resistance: 4.7 kΩ. The bands mean 4.7 kΩ ± 5%: from 4.465 kΩ to 4.935 kΩ.
How to calculate
Reads a 4-, 5- or 6-band resistor colour code (IEC 60062): the resistance, the tolerance, the lowest and highest resistance, and the temperature coefficient.
Example with the default inputs (Number of bands 4 bands, First band Yellow (4), Second band Violet (7), Multiplier band Red (×10²), Tolerance band Gold (±5%)): The bands mean 4.7 kΩ ± 5%: from 4.465 kΩ to 4.935 kΩ.
Method: R = (significant digits) × 10^(multiplier power); lowest = R × (1 − tolerance); highest = R × (1 + tolerance).
- Read the bands from the end where they start; the tolerance band is usually set apart from the others.
- Colours follow IEC 60062:2016; older resistors may use other tolerance colours.
Worked examples
Each example is checked against the calculator on every build.
- Number of bands 4 bands, First band Yellow (4), Second band Violet (7), Multiplier band Red (×10²), Tolerance band Gold (±5%) gives Resistance 4.7 kΩ, Resistance in ohms 4,700, Tolerance 5%, Lowest resistance 4.465 kΩ, Highest resistance 4.935 kΩ.Source: IEC 60062:2016 Marking codes for resistors and capacitors, colour code table as given in “Electronic color code” (https://en.wikipedia.org/wiki/Electronic_color_code, retrieved 2026-10-02)
- Number of bands 5 bands, First band Brown (1), Second band Black (0), Third band Black (0), Multiplier band Brown (×10¹), Tolerance band Brown (±1%) gives Resistance 1 kΩ, Resistance in ohms 1,000, Tolerance 1%, Lowest resistance 990 Ω, Highest resistance 1.01 kΩ.Source: IEC 60062:2016 Marking codes for resistors and capacitors, colour code table as given in “Electronic color code” (https://en.wikipedia.org/wiki/Electronic_color_code, retrieved 2026-10-02)
- Number of bands 6 bands, First band Red (2), Second band Red (2), Third band Black (0), Multiplier band Gold (×10⁻¹), Tolerance band Blue (±0.25%), Temperature coefficient band Brown (100 ppm/K) gives Resistance 22 Ω, Tolerance 0.25%, Lowest resistance 21.945 Ω, Highest resistance 22.055 Ω, Temperature coefficient 100.Source: IEC 60062:2016 Marking codes for resistors and capacitors, colour code table as given in “Electronic color code” (https://en.wikipedia.org/wiki/Electronic_color_code, retrieved 2026-10-02)
- Number of bands 4 bands, First band Green (5), Second band Blue (6), Multiplier band Green (×10⁵), Tolerance band None (±20%) gives Resistance 5.6 MΩ, Lowest resistance 4.48 MΩ, Highest resistance 6.72 MΩ.Source: IEC 60062:2016 Marking codes for resistors and capacitors, colour code table as given in “Electronic color code” (https://en.wikipedia.org/wiki/Electronic_color_code, retrieved 2026-10-02)
How it works
The colours follow IEC 60062:2016.
| Colour | Digit | Multiplier | Tolerance | Temperature coefficient |
|---|---|---|---|---|
| None | – | – | ±20% | – |
| Pink | – | ×10⁻³ | – | – |
| Silver | – | ×10⁻² | ±10% | – |
| Gold | – | ×10⁻¹ | ±5% | – |
| Black | 0 | ×1 | – | 250 ppm/K |
| Brown | 1 | ×10 | ±1% | 100 ppm/K |
| Red | 2 | ×10² | ±2% | 50 ppm/K |
| Orange | 3 | ×10³ | ±0.05% | 15 ppm/K |
| Yellow | 4 | ×10⁴ | ±0.02% | 25 ppm/K |
| Green | 5 | ×10⁵ | ±0.5% | 20 ppm/K |
| Blue | 6 | ×10⁶ | ±0.25% | 10 ppm/K |
| Violet | 7 | ×10⁷ | ±0.1% | 5 ppm/K |
| Grey | 8 | ×10⁸ | ±0.01% | 1 ppm/K |
| White | 9 | ×10⁹ | – | – |
- 4 bands: digit, digit, multiplier, tolerance.
- 5 bands: digit, digit, digit, multiplier, tolerance.
- 6 bands: the 5 bands, then the temperature coefficient.
The digits are read as one whole number (yellow, violet = 47), so resistance R = digits × 10^power. With the tolerance t (5% = 0.05), the lowest resistance is R × (1 − t) and the highest is R × (1 + t). Every value is exact (the digits, powers of ten and tolerances are exact decimals).
Each resistance is shown in the largest of Ω, kΩ (1,000 Ω), MΩ (10⁶ Ω) and GΩ (10⁹ Ω) that leaves at least 1, written in full up to 15 significant figures. The resistance in ohms is also shown as a number. The colour code line shows the digits and the power, for example 47 × 10^2.
Worked examples by hand
Yellow, violet, red, gold (4 bands). Digits 47, multiplier 10², so R = 4,700 Ω = 4.7 kΩ. Tolerance ±5%: 4,700 × 0.05 = 235 Ω, so 4.465 kΩ to 4.935 kΩ.
Brown, black, black, brown, brown (5 bands). Digits 100, multiplier 10¹: R = 1 kΩ ± 1%, so 990 Ω to 1.01 kΩ.
Red, red, black, gold, blue, brown (6 bands). Digits 220, multiplier 10⁻¹: R = 22 Ω ± 0.25% (0.055 Ω), so 21.945 Ω to 22.055 Ω, with 100 ppm/K.
Green, blue, green, no tolerance band. Digits 56, multiplier 10⁵: R = 5,600,000 Ω = 5.6 MΩ ± 20%, so 4.48 MΩ to 6.72 MΩ.
Other questions people ask
How do I read 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. Yellow (4), violet (7), red (×10²), gold (±5%) is 47 × 100 = 4,700 Ω, or 4.7 kΩ ± 5%.
How do I read a 5-band or 6-band resistor?
The first three bands are digits, then the multiplier, then the tolerance. A sixth band gives the temperature coefficient. Brown, black, black, brown, brown is 100 × 10 = 1,000 Ω ± 1%.
Which end do I start reading from?
Start from the band nearest an end. The tolerance band, often gold or silver, is usually set apart from the others. Gold and silver never come first, because they are not digits.
What do gold and silver mean as the multiplier?
Gold multiplies by 0.1 and silver by 0.01, for resistances under 10 Ω. Red, red, gold is 22 × 0.1 = 2.2 Ω.
What does tolerance mean?
How far the real resistance may be from the marked value. A 4.7 kΩ resistor at ±5% can be anywhere from 4,465 Ω to 4,935 Ω. With no tolerance band, it is ±20%.
What is the temperature coefficient?
How much the resistance changes when the resistor warms up, in parts per million per kelvin. At 100 ppm/K, a 1,000 Ω resistor changes by 0.1 Ω for each degree.