Introduction of SMD Resistor Code Calculator

This easy and precise online calculator will assist you in determining the value of any SMD resistor . To begin, enter the three or four-digit code and press the "Calculate" button.

How to Calculate the Value of an SMD Resistor

SMD Resistor Coding Explained with Examples

Most chip resistors are marked with a 3-digit or 4-digit code - the numerical equivalent of the familiar Resistor color code for through-hole components. Recently, a new coding system (the EIA-96) has appeared on precision SMDs.

3-digit code

Standard-tolerance SMD resistors are marked with a simple 3-digit code. The first two numbers will indicate the significant digits, and the third will be the multiplier, telling you the power of ten to which the two significant digits must be multiplied (or how many zeros to add). Resistances of less than 10 ohms do not have a multiplier, the letter 'R' is used instead to indicate the position of the decimal point.

3-digit code examples:

220 = 22 * 10^0 = 22Ω
471 = 47 * 10^1 = 470Ω
102 = 10 * 10^2 = 1000Ω =1kΩ
3R3 = 3.3Ω

4-digit code

The 4-digit code is used for marking precision surface mount resistors . It's similar to the previous system, the only difference is the number of significant digits: the first three numbers will tell us the significant digits, and the fourth will be the multiplier, indicating the power of ten to which the three significant digits must be multiplied (or how many zeros to add). Resistances of less than 100 ohms are marked with the help of the letter 'R', indicating the position of the decimal point.

4-digit Surface Mount Resistor codes examples:

4700 = 470 * 10^0 = 470Ω
2001 = 200 x 10^1 = 2000Ω = 2kΩ
1002 = 100 x 10^2 = 10000Ω = 10kΩ
15R0 = 15.0Ω

EIA-96

Recently, a new coding system (EIA-96) has appeared on 1% SMD resistors . It consists of a three-character code: the first 2 numbers will tell us the 3 significant digits of the resistor value and the third marking (a letter) will indicate the multiplier. You can find all these values in the table below.

What is a SMD Resistor?

Surface-mount resistors are typically small and rectangular in design, and they are black in color. On the other side of the terminal is a tiny, gleaming silver terminal with conductive edges. These resistors are designed to be mounted on top of PCBs and soldered to mating landing pads. Because these resistors are so small, they're normally placed by a robot and then placed in an oven where solder melts and secures them in place. SMD resistors are available in a variety of sizes, including 0805 (0.8mm long by 0.5mm broad), 0603, and 0402. They're ideal for bulk circuit board manufacture or designs in which space is limited. Soldering by hand requires a steady, accurate hand.

Surface Mount Resistors are labeled with a three-digit or four-digit numerical code. So  Surface Mount Resistor Codes are identical to that used on axial resistors to indicate their resistance value. Standard SMD resistors are labeled with a three-digit code, with the first two digits representing the resistance value's first two integers and the third digit representing the multiplier, such as x1, x10, x100, and so on. As an example,
103 = 10 * 1,000 ohms = 10 kΩ (kilo ohms)
392 = 39 * 100 ohms = 3.9 kΩ
563 = 56 * 1,000 ohms = 56 kΩ
105 = 10 * 100,000 ohms = 1 MΩ (Mega ohms)

Surface-mount resistors with values less than 100 are typically expressed as "390," "470," or "560," with the final zero indicating a 10^0 multiplier, which is equivalent to 1. Consider the following scenario:
390 = 39 * 1Ω = 39Ω or 39RΩ
470 = 47 * 1Ω = 47Ω or 47RΩ

Resistor SMD Code

SMD resistors are typically too tiny to have the standard color band code written on them due to their small size. As a result, new resistor SMD codes were created. The three-digit and four-digit systems, as well as an Electronic Industries Alliance (EIA) scheme known as EIA-96, are the most regularly observed codes.

3-Digit SMD Resistor Code System

Standard tolerance resistors are usually coded using a 3-Digit SMD resistor coding method.

This SMD resistor coding scheme employs 3 figures, as the name implies. The important figures are indicated by the first two figures in the code, and the third is a multiplier. This is similar to the coloured rings used for wired resistors, however instead of colors, real numbers are utilized. For resistors less than 100Ω, R is used to indicate the position of the decimal point.

As a result, an SMD resistor with the numbers 472 has a resistance of 47 x 10^2 ohms, or 4.7k. However, resistors with numbers like 100 should be avoided. This is not 100 ohms, but it is 10 x 10^0 or 10 x 1 = 10 ohms since it fits the pattern perfectly.

How to Read 3-Digit SMD Resistor Codes

The significant digits or numbers will be shown by the first two (2) digits or numbers.

The third will be a multiplier (in Power of Ten, i.e. 10^ something) that must be multiplied by the first two (2) significant digits or number, or the third will specify how many Zeros should be added to the first two (2) significant digits or number.

The character "R" is used for the decimal point "." 2.3 Ω = 2R3 Ω.

Resistances less than ten ohms (Ω) do not have a multiplier.

Example on How to Read 3-Digit SMD Resistor Codes

We'll take 4 3-digit SMD resistors as examples. There are one 721, one 2R5, one 816 and one R93.

Example 1 - 721

We use the first two digits of the resistor's base value for the first SMD Resistor 721. Taking the first two digits, we get "72" as our base resistor value.

This base number is then multiplied by 10 to the power of one (The final digit in the code).
R = 72 * 10^1
R = 72 * 10 = 720Ω

We may deduce from this that the resistance of our first SMD resistor is 720 Ohms.

Example 2 - 2R5

We don't need to deal with a multiplier for our second resistor 2R5.

All we have to do is write down the value, with the decimal point placed where the R is in the code.
R = 2R5
R = 2.5

As a result, we may deduce that the resistance of the second resistor is 2.5 Ohms.

Example 3 - 816

We must treat the third resistor (816) in the same manner as we did the first.

First, take the first two numbers such that our SMD resistor's base resistance is 81.

From this, we must recalculate our final number as our "power" of ten. We must now multiply 81 by 10 to the power of three.
R = 81 * 10^6
R = 81,000000 = 81MΩ

We may calculate that the real resistance of the resistor is 81,000000 Ohms or 81M Ohms.

Example 4 - R93

Now we'll go on to our fourth and final resistor (R93).

This SMD resistor is similar to the second example, except the decimal place has been relocated to the front.
R = R93
R = .93

We can rapidly determine that the resistance of this SMD resistor is 0.93 Ohms using this method.

More Examples of 3-Digit SMD Resistor Codes

R12 = 0.12Ω
R34 = 0.34Ω
4R7 = 4.7Ω
3R3 = 3.3Ω
3R4 = 3.4Ω
47R = 47Ω
100 = 10 * 1 = 10Ω
102 = 10 * 100 = 1000Ω or 1kΩ
105 = 10 * 100000 = 1 MΩ
221 = 22 * 10 = 220Ω
250 = 25 * 1 = 25Ω
273 = 27 * 1000 = 27,000Ω (27 kΩ)
313 = 31 * 1000 = 31, 000Ω(31 kΩ)
450 = 45 * 1 = 45Ω
915 = 91 * 100000 = 9,100,000 Ω = 9.1MΩ
901 = 90 * 10 = 900Ω

4-Digit SMD Resistor Code System

The three-digit and four-digit SMD resistor coding systems are identical. The only difference is that one extra digit has been added.

The base resistance value is represented by the first three digits of the four-digit SMD resistor coding scheme . The multiplier's strength is represented by the fourth and final digit.

The multiplier number, like the three-digit system, symbolizes 10 to the power of number.

How to Read 4-Digit SMD Resistor Codes

There is nothing new here; the procedure for reading the value of SMD resistors is the same as described above for the 3 digit SMD roosters. The only difference is that the significant integers are used. In brief, the first two digits of the above approach indicate significant numbers, whereas the first three digits or numbers of this method indicate major numbers. Let's see how we can accomplish it:

The significant digits or numbers will be shown by the first three (3) digits or numbers.

The fourth will be a multiplier (in Power of Ten, i.e. 10 something) that must be multiplied by the first two (3) significant digits or number, or the fourth will indicate how many Zeros should be added to the first two (2) significant digits or figure.

The letter "R" stands in for the decimal point "." as in 11.5 = 11R5 (4-digit SMD resistors) (E96 series).

Resistances less than ten ohms (Ω) do not have a multiplier.

Examples on How to Read 4-Digit SMD Resistor Codes

We'll go through two distinct resistors to give you a better concept of how the four-digit SMD resistor coding works. A 4402 and a 95R21 SMD Resistor are two examples of resistors that we shall look at.

Example 1 - 25R5

25R5 SMD Resistor is our 1st example 4 digit SMD resistor.

Because the number contains the letter "R," we instantly know we don't need to multiply it.

To obtain the real resistance value of our sample resistor, just replace the "R" with a decimal point.

We may deduce that our resistor's value is 95.21 Ohms from this. Therefore, the value of 25R5 SMD resistor is 25.5Ω.

Example 2 - 7992

The second example 4 digit SMD Resistor value is our 7992.

To begin, we must subtract the first three digits from the resistor's stated value, keeping in mind that our base resistance value is 440 Ohms.

We can derive our multiplier of 2 from the resistor's final digit by using the same value.

Then we must multiply our starting value of 440 by 10 to the power of 2. (Our Multiplier).
So, 7992 = 799 * 100 = 79.9kΩ

Therefore, by calculating this, we can determine that the value of our SMD resistor is 44,000 Ohms.

More Examples of 4-Digit SMD Resistor Codes

R102 = 0.102Ω
15R0 = 15.0Ω
0R10 = 0.1Ω
95R21 = 95.21Ω
2500 = 250 * 1 = 250Ω
1000 = 100 * 1 = 100Ω
7201 = 720 * 10 = 7200Ω = 7.2kΩ
1001 = 100 * 10 = 1000Ω = 1kΩ
1004 = 100 * 10000 = 1000,000Ω = 1MΩ
4402 = 440 * 100 = 44,000Ω
4700 = 470 * 1 = 470Ω
1001 = 100 * 10 = 1KΩ
7992 = 799 * 100 = 79.9kΩ
7992 = 799 * 100 = 79,900Ω = 79.9kΩ
1733 = 173 * 1000 = 173,000Ω = 173kΩ

The EIA-96 System

The EIA-96 system is the third and final system for computing the resistance values of SMD resistors. It used a three-digit scheme, with the first two numbers denoting a resistor value from the E96 family.

For each of the 96 potential codes in the E96 series, we have a table that shows the matching value. This table may be found below.

The multiplier is represented by the third digit in the EIA-96 system, which is usually a letter. Use the table below to match the letter to the appropriate multiplier value.

How to Read EIA-96 SMD Resistor Codes

The EIA-96 SMD Resistor Codes labelling technique is a novel approach that only appears on 1% of all SMD resistors. It is made up of three character codes.

The guidelines for determining the value of EIA-96 SMD resistors are outlined below.

The significant digits or numbers will be shown by the first two (2) digits or numbers.

The third "Letter" is a multiplier (in Power of Ten, i.e. 10 something), which must then be multiplied by the first two (2) significant digits.

The codes in Table (1) and (2) must be followed.

The table (1) below shows the multiplier values of various Letters for SMD Resistor Codes using the EIA-96 coding standard.

Also, consider the necessity of table utilization in the cases of reading EIA-96 SMD Resistor Codes table (2).

EIA-96 Code Value Table(1)

Because the EA-96 numbering scheme is based on E96 Series values, you'll need to utilize a chart like ours to get the real base resistance value.

To discover the base resistance value of your EIA-96 SMD resistor , look up the first two numbers in the table below.

SMD Resistance Value Code Table

EIA-96 Multiplier Table(2)

This table may be used to easily calculate the multiplier for SMD resistors using the EIA-96 method. Simply look up the last letter and multiply the value by the multiplier that corresponds to the letter.

EIA SMD RESISTOR CODE SCHEME

Example on How to Read EIA-96 SMD Resistor Codes

Working out the resistance of EIA-96 SMD resistors is a little more difficult than working out the resistance of three or four-digit resistors.

The reason for this is that the EIA-96 references are only codes, therefore you must seek up what the values of the actual numbers are.

We will walk you through three distinct sample resistors to help you learn how to compute the resistance value of an EIA-96 based SMD resistor.

These are some EIA-96 resistor values: 56B, 28X, and 39D.

Example 1 - 56B

The value of this first sample of SMD resistors is 56B.

To begin, we must determine the value of our first two digits.

When we look up 56 in our table, we discover that it corresponds to the base resistance of 374.

We can calculate the multiplier now that we know the base resistance of our SMD resistor is 374.

Looking up the letter B in the multiplier table, we can see that it implies we need to multiply the number by 10. This multiplier value is 10.

Now that we've determined the multiplier, we can calculate the actual resistance of our 11Y resistor by multiplying 374 by 10.
R = 374 x 10
R = 3740

We may deduce from the numbers that the 56B resistor value is 3740 Ohms.

Example 2 - 28X

The 28X EIA-96 SMD Resistor is the second sample resistor we'll look at.

The first step is to determine the basic resistance value. To do so, we must first subtract the first two digits of our resistor.

In this instance, the value is 28. We can get the resistance value of this code by searching it up in our database above.

The next step is to calculate our multiplier. We do this again by looking up the value of X in the multiplier table above. We may calculate the multiplier using the table.

We may now proceed because we have both the basic resistance and the multiplier.

Because the multiplier is 0.1, we know that the resistance of our 28X EIA-96 SMD Resistor example is simply 19.1 Ohms.

Example 3 - 39D

The 39D resistor is our third EIA-96 SMD resistor example.

The first step is to extract the first two digits of the resistor's value, which in this case is 39.

As with the previous two cases, we must look up 39 in our code table to get its value, which is 249.

The multiplier must then be calculated again. We can tell from looking up the letter D in our table that our multiplier is 1000.

We can calculate the actual resistance of the SMD resistor by multiplying our base resistance of 249 by our multiplier of 1000.
R = 249 x 1000
R = 249, 000

Based on these figures, we can compute the resistance of our final sample SMD resistors to be 249, 000 Ohms.

You should now be able to read the value of the SMD resistor code and have a basic grasp of these sorts of resistors.

More Examples of EIA-96 SMD Resistor Codes

01A → Code 01 = 100 with Multiplier A = 1 → 100 * 1 = 100Ω ±1%
01B → Code 01 = 100 with Multiplier B = 10 → 100 * 10 = 1000Ω ±1% = 1KΩ ±1%
01C → Code 01 = 100 with Multiplier C = 100 → 100 * 100 = 10000Ω ±1% = 10KΩ ±1%
38C → Code 38 = 243 with Multiplier C = 100 → 243 * 100 = 24,300Ω ±1% = 24.3KΩ ±1%
01D → Code 01 = 100 with Multiplier D = 1000 → 100 * 1000 = 100000Ω ±1% = 100KΩ ±1%
01E → Code 01 = 100 with Multiplier E = 10000 → 100 * 10000 = 1000000Ω ±1% = 1MΩ ±1%
01F → Code 01 = 100 with Multiplier F = 100000 → 100 * 100000 = 10000000Ω ±1% = 10MΩ ±1%
36H → Code 36 = 100 with Multiplier H = 10 → 232 * 10 = 2320Ω = 2.32 kΩ ±1%
01X → Code 01 = 100 with Multiplier X = 0.1 → 100 * 0.1 = 10Ω ±1%
66X → Code 66 = 100 with Multiplier X = 0.1 → 475 * 0.1 = 47.5Ω ±1%
01Y → Code 01 = 100 with Multiplier Y = 0.01 → 100 * 0.01 = 1Ω ±1%
85Z → Code 85 = 750 with Multiplier Z = 0.001 → 750 * 0.001 = 0.75Ω ±1%
92Z → Code 92 = 887 with Multiplier Z = 0.001 → 887 x 0.001 = 0.887Ω ±1%

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