How to Calculate value of SMD resistor

SMD resistor built with a Surface Mounting Technology known as Surface Mount Device. This resistors are marked with three and four digit codes to indicate their resistance values. Below are the methods to read SMD resistor values.

Reading 3 digit codes

1. The first two digit number will indicate the significant digits or number.
2. The third one will treat as multiplier and then first two digits should multiply by this third digit or third digit will decide that how many zeros should be add to firs two digits.
3. Some times the letter 'R' is also present in the coding of resistor this letter indicates the decimal point "." i.e. 1R1 = 1.1
4. Resistance below 10ohm do not have multiplier i its coding.

Examples of 3 digit codes

330 = 33 × 10⁰ = 33 × 1 = 33Ω
831 = 83 × 10¹ = 83 × 10 = 830Ω  

73R1 = 73.1Ω

Reading 4 digit codes

1. The method is same as mention in previous 3 digit codes only the difference is with the significant numbers.
2. The first three digit will indicate the significant digits or numbers.
3. The fourth one will treat as multiplier and then first three digits should multiply by this fourth digit or fourth digit will decide that how many zeros should be add to firs three digits.

Example of 4 digit codes

3330 = 333 × 10⁰ = 333 × 1 = 333Ω
8301 = 830 × 10¹ = 830 × 10 = 8300Ω  

73R1 = 73.1Ω

Reading EIA 96 Codes

The method is new which is applicable to only 1% of all SMD resistors. It consist 3 character codes. The method is explain as follows:

1. The first two digit will indicate the significant digits.
2. The third letter is a multiplier.
3. The codes are as follows as shown in table.

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

Examples on EIA 96 Codes

01F   =      10M

01E   =     1MΩ

01C   =     10kΩ

01B   =       1kΩ

01A   =     100Ω

01X    =       10Ω

01Y   =        1Ω