3.9 kΩ resistor colour code
Four bands: Orange · White · Red · Gold. The first two give the digits, the third multiplies, the fourth states how far off the real part may be.
Nominal
3.9 kΩ
3,900 ohms
Real range at ±5%
3.705 kΩ – 4.095 kΩ
A gold band allows this much drift.
Series
E12
Held in almost every parts drawer.
Band by band
| Band | Colour | Meaning |
|---|---|---|
| 1 | Orange | 1st digit — 3 |
| 2 | White | 2nd digit — 9 |
| 3 | Red | Multiplier — ×100 |
| 4 | Gold | Tolerance — ±5% |
How much it can take
Current and dissipation across the resistor, and the package you need. The suggested rating keeps a factor of two in hand, which is what anyone building a board actually does.
| Across it | Current | Dissipated | Package to pick |
|---|---|---|---|
| 3.3 V | 846 µA | 2.79 mW | 1/8 W |
| 5 V | 1.28 mA | 6.41 mW | 1/8 W |
| 12 V | 3.08 mA | 36.9 mW | 1/8 W |
| 24 V | 6.15 mA | 148 mW | 1/2 W |
What you can actually get
Parts made
186
59th most of 1,465 values
In stock
49,280
across 5 of them
Cheapest at 100
$0.0017
each
Tolerances sold
±0.01% to ±10%
8 grades in all
Packages: 1206, 0805, 0603, 0402, 1210, 2512, 0612, 1020. Ratings: 30mW to 10W.
What ten of them actually cost
The price everyone quotes is the reel price. If you want ten, you cannot buy the reel — and the real figure is usually several times higher per piece.
Ten pieces
$0.15
$0.015 each · Cut Tape (CT) · minimum order 1
The reel price
$0.00127
each, but only from 100,000 pieces up
Sitting in stock
3,368,857
across 27 part numbers
Per piece, ten costs 11.8× the reel price. That gap is why a handful of resistors never costs what the headline price suggests.
Stocked in ±1% and ±5%, rated 1/20 W to 1/4 W.
Cheapest part you can buy ten of: CR0402-FX-3901GLF by Bourns Inc. — see it at Digi-Key.
Assembly stock from the JLCPCB library, read 2026-09-24. Retail prices and stock from Digi-Key, read 2026-09-24. Prices move — check the product page before ordering. That is what a board house will place for you — not everything a distributor sells.
The same value, marked differently
Five bands
OrangeWhiteBlackRedBrown
Three significant digits and a ±1% band.
Values that can overlap this one
At ±5% the tolerance bands of neighbouring values run into each other. A part sold as one of these could measure the same as a 3.9 kΩ — which is why measuring beats reading when it matters.
- 3.6 kΩ3.42 kΩ–3.78 kΩ
- 3.74 kΩ3.7026 kΩ–3.7774 kΩ
- 3.83 kΩ3.7917 kΩ–3.8683 kΩ
- 3.92 kΩ3.8808 kΩ–3.9592 kΩ
- 4.02 kΩ3.9798 kΩ–4.0602 kΩ
- 4.12 kΩ4.0788 kΩ–4.1612 kΩ
- 4.3 kΩ4.085 kΩ–4.515 kΩ
If you do not have one
Standard values that land within 1% of 3.9 kΩ when combined.