SMD Resistor Code; Surface Mount Resistor Part Markings

SMD resistor sizes 0201, most 0402, and some 0603 are not marked due to their small physical size. Resistance verification on these will have to be done by an actual measurement.

For lower ohm resistors with markings, it is common to see an “R”, an Ohm symbol, or another character used for the decimal place. Below are a couple examples of this:

0.22 Ohm (220mOhm):

0.02 Ohm (20mOhm):

-If the multiplier (last digit) is a zero, this also means a decimal:
24 Ohm:

For higher ohm resistors with markings it is common to see a multiplier with digits 1-9 representing the number of zeros:
10,000 Ohm (10kOhm):

10,000 Ohm (10kOhm):

*Typically, 3-character markings are +/- 5% tolerance, 4-character markings are +/- 1% tolerance.

There is another marking method known as the EIA - 96 MARKING RULE, in which the part marking values are based from a table similar to below.

The the first two-digit “Code” represents the “Value”, and the “Letter” represents the multiplier, or number of zeros to add or subtract.

For example, AC0603FR-071K21L is marked “09B

  • “09” Code calls out 121 (Ohms) Value
  • B” calls out the multiplier 1x10

Therefore, marking code “09B” calls out a resistance value of 1210 Ohm, or 1.21kOhm.

There are sometimes slight table variations between manufacturers, but will result in the same value regardless, below table is a variation example:

See also:
Resistor Temperature and Power Rating Relationship
Yageo Resistor Part Numbering RC_L Series
Yageo MMF Resistor Part Number Breakdown
Identify Yageo AC0603FR-071K21L Chip Resistor Marking