🎛️ 4-Band Resistor Color Code Decoder
A resistor color code calculator that runs both ways: bands to ohms, and the colors for 1k, 10k and 100k — plus which values actually exist.
47 is a standard value. It appears in the E12 series, so it is stocked even in 10% tolerance. You can actually buy this resistor.
What 4-Band Resistor Color Code Decoder Does
Four colored bands encode a resistance. The first two are digits, the third multiplies by a power of ten, and the fourth states how far the real part is allowed to drift from the printed value. Yellow, violet, red, gold reads as 4, then 7, then ×100 — 4,700 ohms, give or take 5%.
That last clause matters more than beginners expect. A ±5% band on 4.7k means the actual component measures somewhere between 4,465 and 4,935 ohms, and the manufacturer has met the specification anywhere in that window. Precision is bought, not assumed: the tolerance band is the honest part of the label.
Most calculators, including the strongest of them, only run in one direction — you feed in colors and get ohms. But a large share of the people searching already know the value they need and want the colors, or want to check the value they are holding is one that actually exists. Both directions are covered here.
The second of those is the part almost nobody explains. Resistors are not made in every value. They come in the E-series preferred numbers, which is why every parts drawer contains 4.7k and none contains 5k, and why a color combination can be perfectly legal to read yet correspond to a component you cannot buy.
How to Use 4-Band Resistor Color Code Decoder
- Select color bands for Digit 1, Digit 2, Multiplier, and Tolerance
- View the real-time visual resistor rendering update
- Read decoded resistance in standard metric notation (kΩ, MΩ)
Formula Used by 4-Band Resistor Color Code Decoder
Reading a four-band resistor
R = (digit₁ × 10 + digit₂) × multiplier, ± tolerance
- digit₁, digit₂
- Bands 1 and 2 — black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, gray 8, white 9
- multiplier
- Band 3 as a power of ten — black ×1, brown ×10, red ×100, orange ×1k, yellow ×10k, green ×100k, blue ×1M; gold ×0.1 and silver ×0.01
- tolerance
- Band 4 — gold ±5%, silver ±10%, brown ±1%, red ±2%; no band at all means ±20%
Worked example
Yellow, violet, red, gold
- Yellow = 4, violet = 7, so the significant figures are 47
- Red multiplier = ×100
- 47 × 100 = 4,700 Ω = 4.7 kΩ
- Gold = ±5%, so 4,700 × 0.95 and 4,700 × 1.05
Result: 4.7 kΩ, guaranteed between 4,465 Ω and 4,935 Ω
Going the other way — value to colors
Take the first two significant figures, then count the remaining zeros for the multiplier
- significant figures
- The first two digits of the value, which become bands 1 and 2
- multiplier
- How many powers of ten separate those two digits from the full value
Worked example
You need 10 kΩ
- 10,000 has significant figures 1 and 0 → brown, black
- 10 × 1,000 = 10,000, so the multiplier is ×1k → orange
- For a 5% part, add gold
Result: Brown, black, orange, gold
Color codes for the values people actually search for
Four-band, with a gold tolerance band for ±5%. These are the value-to-color lookups no calculator on the first page of results offers.
| Value | Band 1 | Band 2 | Multiplier | Standard value? |
|---|---|---|---|---|
| 100 Ω | Brown | Black | Brown (×10) | Yes — E12 |
| 220 Ω | Red | Red | Brown (×10) | Yes — E12 |
| 330 Ω | Orange | Orange | Brown (×10) | Yes — E12 |
| 470 Ω | Yellow | Violet | Brown (×10) | Yes — E12 |
| 1 kΩ | Brown | Black | Red (×100) | Yes — E12 |
| 2.2 kΩ | Red | Red | Red (×100) | Yes — E12 |
| 4.7 kΩ | Yellow | Violet | Red (×100) | Yes — E12 |
| 10 kΩ | Brown | Black | Orange (×1k) | Yes — E12 |
| 47 kΩ | Yellow | Violet | Orange (×1k) | Yes — E12 |
| 100 kΩ | Brown | Black | Yellow (×10k) | Yes — E12 |
| 1 MΩ | Brown | Black | Green (×100k) | Yes — E12 |
The full band reference
Which column applies depends on the band position. The standard is IEC 60062.
| Color | Digit | Multiplier | Tolerance |
|---|---|---|---|
| Black | 0 | ×1 | — |
| Brown | 1 | ×10 | ±1% |
| Red | 2 | ×100 | ±2% |
| Orange | 3 | ×1,000 | — |
| Yellow | 4 | ×10,000 | — |
| Green | 5 | ×100,000 | ±0.5% |
| Blue | 6 | ×1,000,000 | ±0.25% |
| Violet | 7 | ×10,000,000 | ±0.1% |
| Gray | 8 | — | ±0.01% |
| White | 9 | — | — |
| Gold | — | ×0.1 | ±5% |
| Silver | — | ×0.01 | ±10% |
| No band | — | — | ±20% |
The E12 series — why only these values exist
Twelve values per decade, each about 21% above the last. Multiply any of them by any power of ten to get a real, purchasable resistor.
| E12 value | Common realizations |
|---|---|
| 10 | 10 Ω · 100 Ω · 1 kΩ · 10 kΩ · 100 kΩ · 1 MΩ |
| 12 | 120 Ω · 1.2 kΩ · 12 kΩ |
| 15 | 150 Ω · 1.5 kΩ · 15 kΩ |
| 18 | 180 Ω · 1.8 kΩ · 18 kΩ |
| 22 | 220 Ω · 2.2 kΩ · 22 kΩ |
| 27 | 270 Ω · 2.7 kΩ · 27 kΩ |
| 33 | 330 Ω · 3.3 kΩ · 33 kΩ |
| 39 | 390 Ω · 3.9 kΩ · 39 kΩ |
| 47 | 470 Ω · 4.7 kΩ · 47 kΩ |
| 56 | 560 Ω · 5.6 kΩ · 56 kΩ |
| 68 | 680 Ω · 6.8 kΩ · 68 kΩ |
| 82 | 820 Ω · 8.2 kΩ · 82 kΩ |
How to Read Your Result
Why the E-series values look so arbitrary
They are not arbitrary at all — they are a geometric series. E12 steps by the twelfth root of ten, about 1.21, so each value sits roughly 21% above the previous one. That spacing is chosen to match ±10% tolerance: the top of one value's range almost exactly meets the bottom of the next. A 39k part can measure up to 42,900 ohms and a 47k part down to 42,300, so between them they cover the gap with no hole and almost no overlap. Tighter tolerances get denser series — E24 for 5% parts steps by about 10%, and E96 for 1% parts by about 2.4%.
Which end to start from
Read from the end where the bands are bunched together. There is a deliberately wider gap before the tolerance band, leaving it isolated at the far end. Gold and silver are almost always tolerance bands, so if you see one, that end is the right-hand end. Getting this backwards is the most common beginner error and it is not a small one: brown-black-red is 1,000 ohms, and read in reverse red-black-brown is 200.
The tolerance band is a promise about a range
A ±5% 4.7k resistor is not a 4.7k resistor. It is a component the manufacturer guarantees falls between 4,465 and 4,935 ohms, and any value in that window meets the specification. For most circuits that is entirely fine. Where it is not — precision dividers, timing references, current sensing — you want 1% or better parts, which is what the extra significant-figure band on five-band resistors is for.
When the colors are unreadable
Bands fade with heat and age, brown and red are hard to separate on small parts, and some manufacturers use body colors that shift the apparent hue. A multimeter settles it in seconds and is the right move whenever the reading matters. Bear in mind that a resistor already soldered into a circuit will often read low, because you are measuring it in parallel with everything else connected across it.
Surface-mount parts do not use colors at all
The color code belongs to through-hole axial resistors. Surface-mount resistors are printed with numeric codes instead: three digits where the last is the number of zeros, so 472 means 4,700 ohms, or a four-digit version for 1% parts where 4701 means 4,700. Some very small parts use the EIA-96 system, which combines a two-digit code with a letter multiplier.
Limitations & Accuracy Notes
- This calculator reads four-band resistors. Five- and six-band parts add a third significant figure, and a sixth band is usually the temperature coefficient in ppm/K, although on some military-specification parts it denotes the failure rate per 1,000 hours instead.
- A readable color combination is not necessarily a real part. The tool flags values outside the E-series, but availability also depends on power rating, package and supplier stock.
- Faded, discolored or heat-damaged bands cannot be read reliably by any method. Measure with a multimeter when the value matters.
- The tolerance range shown is the manufacturing specification at room temperature. Actual resistance also drifts with temperature according to the part's temperature coefficient, which the four-band code does not encode.
- This is not a substitute for the datasheet. Power rating, voltage rating and temperature coefficient are not carried in the color bands at all, and choosing a resistor on resistance alone is how components end up burning out.
Frequently Asked Questions
What is the color code for a 1k resistor?
How do the four bands work?
Why does 4.7k exist but 5k does not?
Which end do I start reading from?
What do 5-band and 6-band resistors mean?
How do I know which end to read from?
What is the difference between 4, 5 and 6-band resistors?
What do gold and silver mean as multipliers?
What are E-series values?
Are SMD resistors color coded?
Is my data stored?
References & Further Reading
- IEC 60062 — Marking codes for resistors and capacitors — The international standard defining the color band scheme, the numeric SMD codes and the EIA-96 system
- IEC 60063 — Preferred number series for resistors and capacitors — The standard behind the E6, E12, E24, E48, E96 and E192 series that determine which values are manufactured