Resistor color code calculator
Colour bands to ohms — and ohms to colour bands.
Read from the end where the bands are bunched; the tolerance band stands apart.
4.7 kΩ ±5%
- Range
- 4.465 kΩ – 4.935 kΩ
- Standard value in
- E12, E24
Bands for a value
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Example
Example: sorting a starter kit’s resistors — 220 Ω, 1 kΩ and 10 kΩ
A first electronics project needs a 220 Ω resistor for each LED and a 10 kΩ one for a push button, picked out of a mixed bag. Read each one from the end where the bands are bunched; the tolerance band, gold on these, stands a little apart.
- 4 bands red, red, brown, gold: 2, 2, ×10 = 220 Ω ±5%, anywhere from 209 to 231 Ω. A standard value in E12 and E24.
- Brown, black, red, gold is 1 kΩ and brown, black, orange, gold is 10 kΩ: only the multiplier changes, ×100 then ×1k.
- A 5-band one reads red, red, black, black, brown: 220 Ω ±1%. Read backwards it gives 10 kΩ ±2%, also a standard value, so look for the tolerance band set apart.
- The other way round: type 4k7 under “Bands for a value” to see yellow, violet, red, gold on 4 bands, or yellow, violet, black, brown, brown on 5.
| Bands | Value | Range |
|---|---|---|
| Red, red, brown, gold | 220 Ω ±5% | 209–231 Ω |
| Brown, black, red, gold | 1 kΩ ±5% | 950 Ω–1.05 kΩ |
| Brown, black, orange, gold | 10 kΩ ±5% | 9.5–10.5 kΩ |
| Yellow, violet, red, gold | 4.7 kΩ ±5% | 4.465–4.935 kΩ |
| Red, red, black, black, brown (5 bands) | 220 Ω ±1% | 217.8–222.2 Ω |
| Brown, black, black, red, red (the same, read backwards) | 10 kΩ ±2% | 9.8–10.2 kΩ |
The LED and button resistors are found in three readings. When a 5-band resistor gives a sensible value both ways, take the reading whose last band is set apart from the others; on precision resistors that is usually brown, ±1%.
How it works
- Choose 4, 5 or 6 bands, then pick each band’s colour from the end where the bands are bunched.
- Read the value, the tolerance range and whether it is a standard E12, E24 or E96 value.
- Or type a value such as 4k7 or 220 under “Bands for a value” to see which colours it has.
Frequently asked questions
- How do I read a 4-band resistor?
- The first two bands are digits, the third multiplies, the fourth is the tolerance: yellow, violet, red, gold is 4, 7, ×100 = 4.7 kΩ ±5 % (4.465–4.935 kΩ).
- What changes with 5 or 6 bands?
- Five bands have three digits before the multiplier, for precision resistors (usually ±1 % or better). A sixth band gives the temperature coefficient, in ppm per kelvin.
- Which end do I start from?
- From the end where the bands sit close together; the tolerance band — often gold, silver or brown — usually stands a little apart. If a reading isn’t a standard value, try the other way round.
- What are E12 and E24?
- The series of values resistors are made in: E12 has 12 values per decade (1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2), E24 has 24 and E96 96. The page tells you the nearest standard value when yours isn’t one.
- Why does my 5-band resistor read 220 Ω one way and 10 kΩ the other?
- Red, red, black, black, brown is 220 Ω ±1%; the same bands read from the other end, brown, black, black, red, red, are 10 kΩ ±2%. Both are standard values, so the series check cannot tell them apart. Start from the end where the bands are bunched: the tolerance band sits a little apart.
- Which colours does a 4.7k or 330k resistor have?
- Type the value under “Bands for a value”. 4k7 (or 4.7k) is yellow, violet, red, gold on 4 bands and yellow, violet, black, brown, brown on 5; 330k is orange, orange, yellow, gold on 4 bands and orange, orange, black, orange, brown on 5.
- Is anything uploaded?
- No. It works in your browser.