121 Ω resistor colour code
Five bands: Brown · Red · Brown · Black · 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
121 Ω
121 ohms
Real range at ±1%
119.79 Ω – 122.21 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 | Brown | 1st digit — 1 |
| 2 | Red | 2nd digit — 2 |
| 3 | Brown | 3rd digit — 1 |
| 4 | Black | Multiplier — ×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 | 27.3 mA | 90 mW | 1/4 W |
| 5 V | 41.3 mA | 207 mW | 1/2 W |
| 12 V | 99.2 mA | 1.19 W | 5 W |
| 24 V | 198 mA | 4.76 W | no standard part — needs a power resistor or a heatsink |
What you can actually get
Parts made
94
280th most of 1,465 values
In stock
0
across 0 of them
Cheapest at 100
$0.0086
each
Tolerances sold
±0.01% to ±1%
6 grades in all
Packages: 1206, 0805, 0603, 0402, 2512, 1210, 2010, 0201. Ratings: 30mW to 6W.
Assembly stock from the JLCPCB library, read 2026-09-24. 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 121 Ω — which is why measuring beats reading when it matters.
If you do not have one
Standard values that land within 1% of 121 Ω when combined.