Resistor Color Code Calculator
Select the color bands to decode the resistance value, or enter a value to find its color code. Supports 4, 5, and 6-band resistors.
1st digit
2nd digit
Multiplier
Tolerance
Result
Value → Color Bands
Enter a resistance value (e.g. 4.7k, 1M, 470) and press Enter.
Color Code Reference Table
| Color | Digit | Multiplier | Tolerance | Temp. coeff. |
|---|---|---|---|---|
| Black | 0 | ×1 Ω | — | 250 ppm/°C |
| Brown | 1 | ×10 Ω | ±1% | 100 ppm/°C |
| Red | 2 | ×100 Ω | ±2% | 50 ppm/°C |
| Orange | 3 | ×1 kΩ | — | 15 ppm/°C |
| Yellow | 4 | ×10 kΩ | — | 25 ppm/°C |
| Green | 5 | ×100 kΩ | ±0.5% | 20 ppm/°C |
| Blue | 6 | ×1 MΩ | ±0.25% | 10 ppm/°C |
| Violet | 7 | ×10 MΩ | ±0.1% | 5 ppm/°C |
| Grey | 8 | ×100 MΩ | ±0.05% | 1 ppm/°C |
| White | 9 | ×1 GΩ | — | — |
| Gold | — | ×0.1 Ω | ±5% | — |
| Silver | — | ×0.01 Ω | ±10% | — |
How to read resistor color codes
Resistors use colored bands printed on their ceramic body to encode their resistance value, tolerance, and — for precision types — the temperature coefficient. Each color maps to a digit (0–9), a multiplier (×1 Ω to ×1 GΩ), and optionally a tolerance or ppm rating.
4-band resistors
The most common type. Two digit bands + multiplier + tolerance (Gold = ±5%, Silver = ±10%). Found in most general-purpose circuits.
5-band resistors
Precision resistors (±1% or better). Three digit bands allow values like 1.00 kΩ to be expressed unambiguously. Brown tolerance band = ±1%.
6-band resistors
Adds a 6th band for the temperature coefficient (ppm/°C) — how much the resistance drifts with temperature changes. Used in precision and high-reliability designs.
Tip: always read bands left-to-right, starting from the end closest to the first color band. The tolerance band (Gold or Silver) is always on the right with a larger gap from the other bands.
What the color rings actually encode
The colored rings are not decoration: they form a number. The whole reading comes down to a single formula, R = (significant digits) × multiplier. The significant digits come from the first rings — two on a 4-band resistor, three on a 5- or 6-band one — and the multiplier, read on the following ring, is a power of ten (×1, ×10, ×100, ×1 k…). The next ring gives the tolerance t, in percent.
The tolerance is not a detail: it defines the range within which the manufacturer guarantees the component, from R − R × t to R + R × t. A 10 kΩ ±5 % is compliant between 9.5 kΩ and 10.5 kΩ; the same value at ±1 % stays between 9.9 kΩ and 10.1 kΩ. On 6-band models, the last ring gives the temperature coefficient in ppm/°C, i.e. the drift: a 1 kΩ at 50 ppm/°C varies by about 1000 × 50 × 10−6 × 30 ≈ 1.5 Ω if the circuit heats up by 30 °C.
Two worked examples, in both directions
Reading. You pull a resistor out of the drawer marked red, red, brown, gold. Red = 2 and red = 2, so the digits give 22. Brown in the third position means ×10: 22 × 10 = 220 Ω. Gold = ±5 %, i.e. ±11 Ω, so a real value between 209 Ω and 231 Ω. This is exactly the series resistor for a red LED on 5 V: I = (5 − 2) / 220 ≈ 13.6 mA, and the dissipated power P = I² × R ≈ 0.041 W, well within the limits of 1/4 W resistors.
Encoding. The other way around, to mark 4.7 kΩ with 5 bands: write the value in ohms, 4700, take the first three digits 4 — 7 — 0 (yellow, violet, black) then the multiplier ×10 (brown); a fifth brown ring indicates ±1 %. The same 4.7 kΩ in 4 bands becomes yellow, violet, red (×100), gold. To check the resulting combination or calculate the current flowing through it, use the Ohm's law calculator.
Mistakes that throw off the reading
- Direction. Read from left to right, placing the tolerance ring (gold or silver, often set apart by a wider gap) on the right. Read backwards, a 220 Ω would read as brown, red, red, i.e. 1.2 kΩ.
- Dark colors. Brown, red and orange blend together on a body yellowed by heat, and violet can be mistaken for blue under dim light. If in doubt, measure: one of the multimeters set to Ω setting settles it in two seconds, resistor out of circuit, without your fingers on both leads.
- Power is not encoded. No ring indicates the wattage; only the body size does. A correct but undersized value heats up and drifts — move to 1/2 W resistors when the calculation exceeds half the rating.
- Standard values. The E12 and E24 series only exist in fixed steps (10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82 and their decades). No point looking for 237 Ω at ±5 %: it's obtained by combining resistors, which the series and parallel resistor calculator solves.
- The package. SMD models have no color rings but a printed numeric code; they fall under the SMD resistor code calculator.
Frequently asked questions
What is the color code of a 220 Ω resistor?
In 4 bands: red, red, brown, gold (2 — 2 — ×10, ±5 %). In 5-band precision form: red, red, black, black, brown (2 — 2 — 0 — ×1, ±1 %).
How do you read a 5-band resistor?
The first three rings give three digits, the fourth gives the multiplier, and the fifth gives the tolerance. Yellow-violet-black-brown-brown reads as 470 × 10 = 4.7 kΩ ±1 %.
Which direction should you read the rings in?
Put the tolerance ring on the right: it's gold or silver, or the one set apart from the others by a wider gap. If no clue is visible, read both ways and keep the result that matches a standard value.
Why doesn't my multimeter reading match the ring values?
A deviation within the tolerance range is normal. A larger deviation almost always comes from measuring the component while it's still soldered in the circuit, or from your fingers creating a parallel path across the probes.
How do you recognize a precision resistor?
It has five or six bands and a tolerance of ±2 % or better (red ±2 %, brown ±1 %, green ±0.5 %, blue ±0.25 %, violet ±0.1 %), often on a blue or light beige metal-film body.