330 Ω resistor color code
A 330 Ω resistor is Orange, Orange, Brown, Gold: 33 × 10 = 330 Ω, ±5%, so anything from 313.5 to 346.5 Ω is in spec.
33 × 10 = 330 Ω
5-band version
Orange · Orange · Black · Black · Brown = 330 Ω ±1%
330 × 1 = 330 Ω. Range 326.7–333.3 Ω (±1%).
Open the 5-band version
Where you'll meet it
An LED on a Raspberry Pi GPIO pin
Raspberry Pi pins work at 3.3 V and are weaker than Arduino pins, so an LED always gets a resistor. Here GPIO17 drives a red LED through a 330 Ω resistor to ground.
I = (3.3 V − 2.0 V) / 330 Ω ≈ 3.9 mA
That is enough for a clear glow, and well under the 16 mA that one Raspberry Pi pin should give. All the GPIO pins together should stay under 50 mA.
On a 5 V Arduino pin the same resistor gives (5 V − 2.0 V) / 330 Ω ≈ 9.1 mA: brighter, and still safe.
The resistor turns (3.9 mA)² × 330 Ω ≈ 0.005 W into heat, so any ¼ W (0.25 W) part is fine.
2.0 V is a typical red LED forward voltage. Check your LED's datasheet. The pin voltage also sags a little under load, so the real current is slightly lower. Blue and white LEDs drop about 3.0 to 3.3 V, so a 3.3 V pin can push at most (3.3 V − 3.0 V) / 330 Ω ≈ 0.9 mA through one: it looks dim or stays dark.
On SMD parts
Look for 331 or 3300
- 331331 = 33 × 10¹ = 330 Ω (3-digit code).
- 33003300 = 330 × 10⁰ = 330 Ω (4-digit code, usually ±1% parts).
There is no EIA-96 code, because 330 Ω is not an E96 value (the nearest E96 values are 324 Ω and 332 Ω). A part marked 330 is 33 Ω, not 330 Ω.
Don't mix it up
Only band 3 changes
These four share Orange, Orange and Gold. Brown (×10) is 330 Ω; black is ten times less and red ten times more.
33 Ωband 3 black- 330 Ωband 3 brownThis page
3.3 kΩband 3 red
33 kΩband 3 orange
Check it with a meter
Read 313.5–346.5 Ω
- Take the resistor out of the circuit.
- Set the meter to Ω, range 2 kΩ (or auto).
- Touch one probe to each lead. Keep your fingers off the metal: your body is a resistor too.
- Anything from 313.5 to 346.5 Ω is a good ±5% part. A 5-band ±1% part should read 326.7 to 333.3 Ω.
A meter has a small error of its own, so a reading a hair outside the range does not prove the part is bad. Measure again with firm contact before you swap it.
Spot it
Can you find 330 Ω in a pile?
Practise reading it, and its look-alikes, in the resistor challenge.
Try the resistor challenge330 Ω resistor FAQ
Why do Raspberry Pi tutorials use a 330 Ω resistor for an LED?
A Raspberry Pi pin gives 3.3 V and should supply no more than 16 mA. With a typical red LED (about 2.0 V), a 330 Ω resistor sets (3.3 V − 2.0 V) / 330 Ω ≈ 3.9 mA: easy to see and gentle on the pin. On a 5 V Arduino the same part gives about 9.1 mA, so it works there too.
What is the SMD code for a 330 Ω resistor?
331 on 3-digit parts (33 × 10¹) and 3300 on 4-digit parts (330 × 10⁰). There is no EIA-96 code, because 330 Ω is not an E96 value.
What are the 5-band colors for 330 Ω?
Orange, Orange, Black, Black, Brown: 330 × 1 = 330 Ω with ±1% tolerance, so 326.7 to 333.3 Ω.
What does 330R mean?
330R is another way to write 330 Ω. The R stands for ohms and sits where the decimal point would be, so 4R7 means 4.7 Ω. With nothing after the R, 330R is exactly 330 Ω.
Bands, ranges and codes come from the same engine as the calculator. Last reviewed .