330 Ohm Resistor Color Code — Arduino Kit & 3.3 V vs 5 V Matrix

330 Ω & the Arduino starter-kit tradition

Orange · Orange · Brown · Gold → $33 × 10$ = 330 Ω. Both digit bands orange (3) — easy to spot in a mixed pile.

4-band: Orange · Orange · Brown · Gold → 33 × 10 = 330 Ω (±5%) · 5-band (±1%): Orange · Orange · Black · Black · Brown → 330 × 1 = 330 Ω (±1%)

This page is the supply-voltage vs LED brightness reference. Band-reading basics: beginner's guide.

Supply voltage matrix (same 330 Ω, same red LED)

MCU / rail	$V_f ≈ 2 V$	Current ≈ $(V−2)/330$	Visible?
5 V (UNO)	2 V	~9 mA	Yes — kit default
3.3 V (ESP32, Pico 3V3)	2 V	~4 mA	Often dim
3.3 V + blue LED ($V_f≈3 V$)	3 V	~1 mA	Usually insufficient

Takeaway: 330 Ω is optimized for 5 V + red/yellow LED. On 3.3 V projects, jump to 220 Ω or calculate with the LED calculator.

Identify 330 Ω in a mixed resistor strip

1. Look for two orange bands next to each other (digits side)
2. Third band brown (×10), not black (×1 → 33 Ω)
3. Fourth gold on the right (±5%)

If you see	Value
Orange · Orange · Brown · Gold	330 Ω
Orange · Orange · Black · Gold	33 Ω
Orange · White · Brown · Gold	390 Ω

Breadboard wiring checklist (5 V indicator)

1. GPIO → 330 Ω → LED anode (long leg)
2. LED cathode → GND
3. Confirm polarity — reverse LED won't light regardless of correct color code
4. Meter the resistor out-of-circuit if bands are worn

FAQ

What is the 330 ohm resistor color code?

4-band (±5%): Orange, Orange, Brown, Gold. 33 × 10 = 330 Ω (±5%). Actual range: 313.5 Ω – 346.5 Ω.

What is the 330 ohm resistor colour code (5-band)?

Orange · Orange · Black · Black · Brown → 330 × 1 = 330 Ω (±1%). Range: 326.7 Ω – 333.3 Ω.

How do I read a 330 ohm resistor color code?

Read left to right: first bands are digits, then multiplier, then tolerance. For 330 Ω: Orange-Orange-Brown = significant digits & multiplier, Gold = tolerance. Use the color code calculator to verify.

Which end do I start reading a 330 Ω resistor from?

Start from the grouped digit bands (left). The tolerance band (Gold) is on the right — gold and silver are almost always tolerance, not multipliers.

What is the difference between 4-band and 5-band for 330 Ω?

4-band (Orange · Orange · Brown · Gold) gives 33 × 10 = 330 Ω (±5%) with typical ±5% gold tolerance. 5-band (Orange · Orange · Black · Black · Brown) adds a third digit for ±1% precision: 330 × 1 = 330 Ω (±1%) (326.7 Ω – 333.3 Ω).

What is the 330 ohm color code?

Orange, Orange, Brown, Gold (4-band).

330 vs 220 ohm for LEDs?

330 Ω runs lower current (cooler/dimmer); 220 Ω is brighter on the same supply.

Related guides (different topics)

• 220 Ω color code — LED brightness vs 330/470 Ω on 5 V
• 470 Ω color code — textbook LED history & Y-V family
• 1 kΩ color code — divider math & strong pull-ups

Topic cluster

• Values hub — pick by application
• How to read any resistor (method)
• Color code calculator — decode any value
• 4-band decoder on calculator