| 0 | BLACK |
 | |
| 1 | BROWN | ||
| 2 | RED | ||
| 3 | ORANGE | ||
| 4 | YELLOW | ||
| 5 | GREEN | ||
| 6 | BLUE | ||
| 7 | VIOLET |
Tolerance: |
GOLD = ±5% |
| 8 | GREY | SILVER = ±10% | |
| 9 | WHITE | NONE = ±20% | |
Resistors in the Real World
"...you cannot find a 210 ohm resistor, but you can choose 220 ohm ±10%..."
RESISTOR COLOR CODES
Most resistors are labeled using distinctive colored bands which serve to identify their value at a glance. The colors shown below are used for the first three of these bands, as shown. The resistance value consists of a two-digit number followed by a power-of-ten multiplier. The expected tolerance is indicated by a fourth band.
| 0 | BLACK |
| |
| 1 | BROWN | ||
| 2 | RED | ||
| 3 | ORANGE | ||
| 4 | YELLOW | ||
| 5 | GREEN | ||
| 6 | BLUE | ||
| 7 | VIOLET |
Tolerance: |
GOLD = ±5% |
| 8 | GREY | SILVER = ±10% | |
| 9 | WHITE | NONE = ±20% | |
STANDARD RESISTOR VALUES
Because resistors are typically manufactured to a tolerance of ±5% or ±10%, it would not make much sense to make resistors in every possible value from 0 to 99 ohm. Instead, resistors are manufactured and labeled according to the specified tolerance.
Standard resistor values (the first two colored bands) include the following:
| 10 | 11 | 12 | 13 | All these values are available in 5% tolerances,
while 10% resistors are made only with the values
in red.
For each standard value, the expected tolerance overlaps with the next value in the table, within error. Note that this table applies to common 5% or 10% resistors. More expensive precision resistors are available in any value. | |
| 15 | 16 | 18 | 20 | ||
| 22 | 24 | 27 | 30 | ||
| 33 | 36 | 39 | 43 | ||
| 47 | 51 | 56 | 62 | ||
| 68 | 75 | 82 | 91 |
This table implies that, depending on the third colored band, you could buy 22 ohm, 220 ohm, 2200 ohm, or 22k ohm 10% resistors. You will not find 21 ohm, 210 ohm, 2100 ohm, or 21k ohm resistors in your parts box.
Note that with the tolerances included, every value of resistor is covered from 00 to 99...
