100 Ω resistor colour code
Four bands: Brown · Black · Brown · Gold. The first two give the digits, the third multiplies, the fourth states how far off the real part may be.
Nominal
100 Ω
100 ohms
Real range at ±5%
95 Ω – 105 Ω
A gold band allows this much drift.
Series
E6
Held in almost every parts drawer.
Band by band
| Band | Colour | Meaning |
|---|---|---|
| 1 | Brown | 1st digit — 1 |
| 2 | Black | 2nd digit — 0 |
| 3 | Brown | Multiplier — ×10 |
| 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 | 33 mA | 109 mW | 1/4 W |
| 5 V | 50 mA | 250 mW | 1/2 W |
| 12 V | 120 mA | 1.44 W | 5 W |
| 24 V | 240 mA | 5.76 W | no standard part — needs a power resistor or a heatsink |
What you can actually get
Parts made
305
2nd most of 1,465 values
In stock
132,351
across 25 of them
Cheapest at 100
$0.0008
each
Tolerances sold
±0.01% to ±10%
11 grades in all
Packages: 0603, 1206, 0805, 0402, 1210, 2010, 2512, 0201. Ratings: 30mW to 100W.
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
$0.32
$0.032 each · Cut Tape (CT) · minimum order 1
The reel price
$0.00414
each, but only from 100,000 pieces up
Sitting in stock
5,012,234
across 2 part numbers
Per piece, ten costs 7.7× the reel price. That gap is why a handful of resistors never costs what the headline price suggests.
Stocked in ±1%, rated 1/16 W to 1/10 W.
Cheapest part you can buy ten of: CRCW0402100RFKED by Vishay Dale — 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
BrownBlackBlackBrownBrown
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 100 Ω — which is why measuring beats reading when it matters.
- 91 Ω86.45 Ω–95.55 Ω
- 95.3 Ω94.347 Ω–96.253 Ω
- 97.6 Ω96.624 Ω–98.576 Ω
- 102 Ω100.98 Ω–103.02 Ω
- 105 Ω103.95 Ω–106.05 Ω
- 110 Ω104.5 Ω–115.5 Ω
If you do not have one
Standard values that land within 1% of 100 Ω when combined.