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SMD Resistor Codes: How to Find the Value of SMD Resistors

How to Calculate & Find the Value of SMD & EIA-96 SMD Resistor Resistors?

SMD Resistor: Surface Mount Technology

SMD Resistor stands for “Surface Mount device” (Taken out from SMT = Surface Mount Technology) Resistor. These tiny chips are marked with three (3) or four (4) digit codes which are called SMD Resistor codes to indicate their resistance values.

Below are some given roles which help to know the exact value of an SMD resistor by seeing the printed character codes on those tiny chips.

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SMD Resistor Code: How to Find the value of SMD Resistors

Reading 3-Digit SMD Resistor Codes

  • The first two (2) digits or numbers will indicate the significant digits or numbers.
  • The third one will be multiplier (in Power of Ten i.e. 10^ something) and then must be multiply by the first Two (2) significant digits or number or the third one will indicate that how many Zeros should be added to the first Two (2) significant digits or number.
  • The letter “R” is used for Decimal Point “.” i.e. 1.1 Ω = 1R1 Ω
  • Resistances below 10 ohms (Ω) do not have a multiplier.

Examples of 3-Digit SMD Resistor Codes

250 = 25 x 100 = 25 x 1 = 25 Ω (This is only and only 25Ω not 250 Ω)

100 = 10 x 100 = 10 x 1 = 10 Ω

721 = 72 x 101 = 72 x 10 = 720 Ω

102 = 10 × 102 =10 x 100 = 1000Ω or 1kΩ 915 = 91 x 105 = 91 x 100000 = 9,100,000 Ω = 9.1MΩ

4R7 = 4.7Ω

R12 = 0.12 Ω

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Reading 4-Digit SMD Resistor Codes

There is nothing new but the same method to read the value of SMD resistors as mentioned above for the 3 digits SMD roosters. The only difference is that with the significant numbers. In short, in the above method, the first two digits indicate significant numbers while in this method, the first three digits or numbers will show the significant numbers. Lets see how to do it.

  • The first three (3) digits or numbers will indicate the significant digits or numbers.
  • The fourth one will be multiplier (in Power of Ten i.e. 10^ something) and then must be multiply by the first two (3) significant digits or number or the fourth one will indicate that how many Zeros should be add to the first Two (2) significant digits or number.
  • The letter “R” is used for Decimal Point “.” i.e. 11.5 Ω = 11R5 Ω (4-digit SMD resistors (E96 series).
  • Resistances below 10 ohms (Ω) do not have a multiplier.

Also read: Resistor & Types of Resistors

Examples of 4-Digit SMD Resistor Codes

2500 = 250 x 100 = 250 x 1 = 250 Ω (This is only and only 250Ω not 2500 Ω)

1000 = 100 x 100 = 100x 1 = 100 Ω

7201 = 720 x 101 = 720 x 10 = 7200 Ω or 7.2kΩ

1001 = 100 × 101 =100 x 10 = 1000 Ω or 1kΩ

1004 = 100 × 104 =100 x 10000 = 1000,000 Ω or 1MΩ

R102 = 0.102 Ω (4-digit SMD resistors (E96 series)

0R10 = 0.1 x 100 = 0.1 x 1 = 0.1 Ω (4-digit SMD resistors (E24 series)

25R5 = 25.5Ω (4-digit SMD resistors (E96 series))

Reading EIA-96 SMD Resistor Codes

EIA-96 SMD Resistor Codes marking method is a new method which appeared on 1% of all SMD resistors. It consists of 3- Character codes.

Below are the rules to follow to know the value of EIA-96 SMD resistors.

  • The first two (2) digits or numbers will indicate the significant digits or numbers
  • The third one “Letter” is a multiplier (in Power of Ten i.e. 10^ something) and then must be multiplied by the first Two (2) significant digits.
  •  Must follow the codes in Table (1) and (2).

Below is the table (1) to show the multiplier values of different Letters using the EIA-96 coding system for SMD Resistor Codes.

Table (1)

Letters Multipliers
Z 0.001
R or Y 0.01
S or X 0.1
A 1
B or H 10
C 100
D 1000
E 10000
F 100000

Also, look in the examples of reading EIA-96 SMD Resistor Codes for importance the use of table (2)

Table (2)

Code Value Code Value Code Value Code Value
01 100 25 178 49 316 73 562
02 102 26 182 50 324 74 576
03 105 27 187 51 332 75 590
04 107 28 191 52 340 76 604
05 110 29 196 53 348 77 619
06 113 30 200 54 357 78 634
07 115 31 205 55 365 79 649
08 118 32 210 56 374 80 665
09 121 33 215 57 383 81 681
10 124 34 221 58 392 82 698
11 127 35 226 59 402 83 715
12 130 36 232 60 412 84 732
13 133 37 237 61 422 85 750
14 137 38 243 62 432 86 768
15 140 39 249 63 442 87 787
16 143 40 255 64 453 88 806
17 147 41 261 65 464 89 825
18 150 42 267 66 475 90 845
19 154 43 274 67 487 91 866
20 158 44 280 68 499 92 887
21 162 45 287 69 511 93 909
22 165 46 294 70 523 94 931
23 169 47 301 71 536 95 953
24 174 48 309 72 549 96 976

Examples of EIA-96 SMD Resistor Codes

  • 01F =     10M
  • 01E =     1MΩ
  • 01C=     10kΩ
  • 01B =   1kΩ
  • 01A =   100Ω
  • 01X =   10Ω
  • 01Y =   1Ω
  • 66X = 475 x 0.1 = 47.5 …→ (in table (2), 66 = 475 and in table (1), X = 0.1. so 475 x 0.1 = 47.1Ω)
  • 85Z = 750 x 0.001 = 0.75Ω → (in table (2), 85 = 750 and in table (1), Z = 0.001. so 750 x 0.001 = 0.75Ω)
  • 36H = 232 x10 = 2320Ω = 2.32kΩ → (in table (2), 36 = 232 and in table (1), H = 10. so 232 x 10= 2.32kΩ)

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9 Comments

  1. Murthy Challa says:

    very essential and and useful information. Thanq

  2. Upendra singh says:

    This kind of information makes man like engineer.

  3. Tarak nath paul says:

    very useful. thanks.

  4. Abbas M K says:

    very useful tables and lesson thank you

  5. Muhammad Hafeez says:

    Very Useful Information Thanks.

  6. bob alvin pagarigan says:

    any replacement for msd resistor? thanks

  7. very good information thank you for sharing with us…………

  8. en resistencia de superficie 40r2 es 40.7 ohmios? gracias

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