Check a 330 ohm resistor in the calculator
The calculator is set to 330 Ω with a gold tolerance band. Switch to 5 or 6 bands, change the tolerance, or choose “Read the bands” to decode a resistor you are holding.
330 ohm resistor colour bands
A 330 Ω resistor carries the same value in every marking system; only the number of bands changes. Read from the end with the bands bunched closest to it, with the tolerance band, usually gold or brown and set slightly apart, on the right.
| Marking | Colours | Drawing | Where you see it |
|---|---|---|---|
| 4 bands, ±5 % | orange, orange, brown, gold | The most common through-hole marking | |
| 5 bands, ±1 % | orange, orange, black, black, brown | Precision metal-film resistors | |
| 6 bands, ±1 %, 100 ppm/K | orange, orange, black, black, brown, brown | Adds a temperature-coefficient band | |
| 3 bands, ±20 % | orange, orange, brown | Old parts with no tolerance band |
How to read orange, orange, brown, gold
- First band, orange: first digit 3.
- Second band, orange: second digit 3, giving 33.
- Third band, brown: multiply by 10, giving 330 Ω.
- Fourth band, gold: tolerance ±5 %.
On the 5-band version the first three bands are digits (330) and the fourth is the multiplier (×1), which comes to the same 330 Ω. Check any other combination with the resistor color code calculator.
What a 330 ohm resistor should measure
Tolerance is how far the real resistance may sit from the marked value. Measured out of circuit with a meter, a good 330 Ω resistor reads within these limits:
| Tolerance | Band | Lowest | Highest |
|---|---|---|---|
| ±1 % | Brown | 326.7 Ω | 333.3 Ω |
| ±2 % | Red | 323.4 Ω | 336.6 Ω |
| ±5 % | Gold | 313.5 Ω | 346.5 Ω |
| ±10 % | Silver | 297 Ω | 363 Ω |
| ±20 % | None (no band) | 264 Ω | 396 Ω |
Measure it out of circuit, or with one leg lifted: anything connected in parallel in the circuit pulls the reading down. Set a manual meter to the first range above 330 Ω.
Is 330 ohm a standard resistor value?
Yes. 330 Ω belongs to the E6, E12, E24 series of IEC 60063, so it is made in the ±5 % and ±10 % ranges, though not in the ±1 % E96 range. The neighbouring E12 values are 270 Ω below and 390 Ω above. All the series are listed on our E-series resistor values page.
SMD code for 330 Ω
- 3-digit code (usually ±5 %):
331. - 4-digit code (usually ±1 %):
3300. - EIA-96 code (±1 % chips in 0603 and smaller): none: 330 Ω is not an E96 value, so 1 % chips of this value carry the 4-digit code instead.
Decode any chip marking with the SMD resistor code calculator.
Current, power and wattage
By Ohm’s law, I = V ÷ R and P = V² ÷ R. With the whole supply across a 330 Ω resistor:
| Across | Current | Power | Rating to use |
|---|---|---|---|
| 3.3 V | 10 mA | 33 mW | ⅛ W |
| 5 V | 15.2 mA | 75.8 mW | ¼ W |
| 12 V | 36.4 mA | 436 mW | 1 W |
| 24 V | 72.7 mA | 1.75 W | 5 W |
A ¼ W 330 Ω resistor reaches its full rating at 9.08 V (V = √(P × R)). In series with a red LED (about 2 V) on a 5 V supply it passes 9.09 mA. The LED resistor calculator finds the right value for any LED and supply.
What a 330 ohm resistor is used for
330 Ω is a common LED resistor for 5 V when you want a little less brightness than 220 Ω gives, and the usual choice in starter kits for driving optocoupler LEDs and seven-segment displays from logic pins. At 3.3 V it still lights a red LED, dimly.
Mistakes when reading a 330 ohm resistor
The multiplier band moves the value by a factor of ten for every colour step, so it is the band to check twice, in good light. These are the misreadings that catch people out with 330 Ω:
- Brown read as red. Orange, orange, red, gold would be 3.3 kΩ, 10 times too high.
- Brown read as orange. Orange, orange, orange, gold would be 33 kΩ, 100 times too high.
- Reading the 4-band code backwards. It can’t be done: gold is not a digit colour, which is how you know which end comes first.
- Reading the 5-band code backwards. Brown, black, black, orange, orange reads as 100 kΩ ±0.05 %, a plausible value, so this mistake goes unnoticed. The tolerance band is usually a little apart from the others; if you can’t tell, measure it.
Making 330 Ω from other values
No 330 Ω in the drawer? Two common E12 values can stand in, within 1 %: in series, 150 Ω + 180 Ω = 330 Ω; in parallel, 390 Ω ∥ 2.2 kΩ = 331.3 Ω; 560 Ω ∥ 820 Ω = 332.8 Ω. Two 330 Ω resistors give 660 Ω in series and 165 Ω in parallel.
Colour codes for other common values
- 1 ohm resistor: brown, black, gold
- 100 ohm resistor: brown, black, brown
- 220 ohm resistor: red, red, brown
- 470 ohm resistor: yellow, violet, brown
- 1k resistor: brown, black, red
- 4.7k resistor: yellow, violet, red
- 10k resistor: brown, black, orange
- 100k resistor: brown, black, yellow
- 1M resistor: brown, black, green
Colours follow IEC 60062:2016. Codes, ranges and currents on this page are computed by the same engine as the resistor colour code calculator; see our methodology.