SMD code 21R5 — 21.5 Ω
A surface-mount resistor has no bands. This one is a four-digit marking: the R is the decimal point — 21.5 Ω. Parts marked this way are usually ±1% or tighter.
21R5
reads as
21.5 Ω
The same part, in bands
The through-hole version of 21.5 Ω carries 5 colour bands instead.
Everything about 21.5 Ω — power ratings, what ten cost, what is in stock.
Same value, other markings
21.5 Ω is printed several ways depending on the part's precision and size. A board can carry all of them at once.
How much it can take
| Across it | Dissipated | Smallest package that copes |
|---|---|---|
| 5 V | 1.16 W | 5 W |
| 12 V | 6.7 W | no standard part — needs a power resistor or a heatsink |
What you can actually get
Parts made
68
at this value
Ten pieces
$0.21
not the reel price
Common packages
1206 · 0805 · 0603 · 0402
Codes you will mistake it for
One character apart from 21R5. On a 0402 part these are a fraction of a millimetre of printing — worth a second look before you solder.