21 Ω resistor colour code
Five bands: Red · Brown · Black · Gold · Brown. The first three give the digits — a precision value needs all three — then the multiplier, then how far off the real part may be.
Nominal
21 Ω
21 ohms
Real range at ±1%
20.79 Ω – 21.21 Ω
A brown band allows this much drift.
Series
E96
A 1% precision value. Five bands, not four.
Band by band
| Band | Colour | Meaning |
|---|---|---|
| 1 | Red | 1st digit — 2 |
| 2 | Brown | 2nd digit — 1 |
| 3 | Black | 3rd digit — 0 |
| 4 | Gold | Multiplier — ×0.1 |
| 5 | Brown | Tolerance — ±1% |
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 | 157 mA | 519 mW | 2 W |
| 5 V | 238 mA | 1.19 W | 5 W |
| 12 V | 571 mA | 6.86 W | no standard part — needs a power resistor or a heatsink |
| 24 V | 1.14 A | 27.4 W | no standard part — needs a power resistor or a heatsink |
What you can actually get
Parts made
49
637th most of 1,465 values
In stock
0
across 0 of them
Cheapest at 100
$0.0057
each
Tolerances sold
±0.1% to ±1%
4 grades in all
Packages: 0805, 0603, 0402, 1206, 2512, 1210, 0201, 2010. Ratings: 50mW to 2W.
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
$0.31
$0.031 each · Digi-Reel® · minimum order 1
The reel price
$0.00431
each, but only from 100,000 pieces up
Sitting in stock
141,218
across 5 part numbers
Per piece, ten costs 7.2× the reel price. That gap is why a handful of resistors never costs what the headline price suggests.
Stocked in ±1%, rated 1/10 W to 1/4 W.
Cheapest part you can buy ten of: ERJ-2RKF21R0X by Panasonic Industry — 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
Values that can overlap this one
At ±1% the tolerance bands of neighbouring values run into each other. A part sold as one of these could measure the same as a 21 Ω — which is why measuring beats reading when it matters.
If you do not have one
Standard values that land within 1% of 21 Ω when combined.