3.9 ohm resistor color code

The color code for 3.9 Ω is orange, white, gold, gold on a 4-band resistor (±5%) and orange, white, black, silver, brown on a 5-band resistor (±1%).

Color bands

4 bands, ±5%Orange, White, Gold, Gold

5 bands, ±1%Orange, White, Black, Silver, Brown

6 bands, ±1%, 100 ppm/KOrange, White, Black, Silver, Brown, Brown

Open 3.9 Ω in the color code calculator →

Actual value by tolerance

Tolerance	Band	Minimum	Maximum
±1%	Brown	3.861 Ω	3.939 Ω
±2%	Red	3.822 Ω	3.978 Ω
±5%	Gold	3.705 Ω	4.095 Ω
±10%	Silver	3.51 Ω	4.29 Ω

SMD and printed codes

SMD, 3 digits	`3R9`
SMD, 4 digits	`3R90`
SMD, EIA-96	not used for this value
Letter code (IEC 60062)	`3R9`

Current and power at common voltages

Voltage	Current	Power	Resistor rating
3.3 V	846 mA	2.79 W	10 W
5 V	1.28 A	6.41 W	over 10 W
9 V	2.31 A	20.8 W	over 10 W
12 V	3.08 A	36.9 W	over 10 W
24 V	6.15 A	148 W	over 10 W

As an LED resistor

Current through one LED in series with 3.9 Ω:

Supply	Red LED (2.0 V)	White or blue LED (3.2 V)
3.3 V	333 mA	25.6 mA
5 V	769 mA	462 mA
12 V	2560 mA	2260 mA

Above 20 mA: too much for a common 5 mm LED.

LED Resistor Calculator →

Standard series

3.9 Ω is a standard value in the E12, E24 series, so it comes in almost every resistor kit.

Nearby values

← 3.3 Ω 4.7 Ω →

Same first two colors, different multiplier:

39 Ω 390 Ω 3.9 kΩ 39 kΩ 390 kΩ 3.9 MΩ

Frequently asked questions

What are the colors of a 3.9 Ω resistor?

On a 4-band resistor: orange, white, gold, gold. On a 5-band resistor: orange, white, black, silver, brown.

What is the SMD code for 3.9 Ω?

3R9 on 3-digit resistors and 3R90 on 4-digit (1%) resistors.

How much current flows through a 3.9 Ω resistor at 5 V?

1.28 A, dissipating 6.41 W: more than a standard resistor can handle.

Which resistors get mixed up with 3.9 Ω?

orange, white, silver, gold is 390 mΩ and orange, white, black, gold is 39 Ω: only the third band changes, so check it carefully.