# How to Read a Barcode (2023 Update)

3.4 minutes

In this article, we provide you with a step-by-step process on how to read barcode numbers with a real-world example to better illustrate the process for you.

## How to Read a Barcode

Here's a step-by-step guide on how to read a barcode:

### 1. Understand the Barcode Basics

Barcodes consist of a series of black and white bars representing different characters. The pattern of these bars encodes information, and various types of barcodes exist, such as UPC (Universal Product Code) and QR codes. Familiarize yourself with the type of barcode you’re dealing with.

### 2. Decode the Numbers

Most barcodes have numbers beneath the bars. Each number corresponds to a specific width of a black or white bar. For example, in a typical UPC-A barcode, the number "0" might represent a narrow white bar, while "1" could represent a narrow black bar.

### 3. Use Online Barcode Decoding Tools

Numerous online tools can help decode barcodes using the numbers beneath the bars. Websites like Barcode Lookup or Online Barcode Reader allow you to enter the numbers manually and get instant results about the product associated with the barcode.

### 4. Mobile Apps for Barcode Decoding

Several mobile apps can decode barcodes using your smartphone’s camera. Apps like "Barcode Scanner" for Android or "Barcode Reader" for iOS allow you to scan the barcode using your phone’s camera, instantly providing information associated with the product.

### 5. Understand Check Digits

Some barcodes have a check digit at the end. This digit is calculated from the other digits in the barcode and is used to verify the accuracy of the scanned data. Online tools or mobile apps can often calculate check digits automatically, ensuring the integrity of the decoded information.

Example: Suppose you have the first 11 digits of a UPC-A barcode: 49681249545.

Step 1: Add the Digits in Odd Positions (1st, 3rd, 5th, 7th, 9th, and 11th).

4+6+1+4+2+5=22

Step 2: Multiply the Result by 3

22×3=66

Step 3: Add the Digits in Even Positions (2nd, 4th, 6th, 8th, and 10th).

9+8+2+9+4=32

Step 4: Add the Results from Step 2 and Step 3

66+32=98

Step 5: Calculate the modulus 10 of the result from step 4.

98mod  10=8

Step 6: Subtract the result from step 5 from 10 to get the check digit.

10−8=2

Therefore, the calculated check digit for the first 11 digits "49681249545" of the UPC-A barcode is 2. This check digit ensures that the barcode reader can verify the accuracy of the scanned data by performing a similar calculation.

### 6. Utilize Excel or Google Sheets

For small-scale operations, you can use spreadsheet software like Excel or Google Sheets to manually decode barcodes. Create a table with corresponding numbers and their representations, then input the numbers from the barcode. The spreadsheet will instantly display the encoded information.

### 7. Learn the Morse Code Method

In Morse code, dots and dashes represent letters and numbers. Similarly, barcodes consist of bars (dashes) and spaces (dots). By translating these bars and spaces into Morse code, you can decode the information manually. For example, a thick black bar can represent a dash, and a thin white bar can represent a dot.

### 8. Understand Quiet Zones and Start/Stop Characters

Barcodes have quiet zones at the beginning and end, which are blank spaces indicating the start and end of the barcode. Additionally, start and stop characters signify the beginning and end of the data. Understanding these elements helps you identify where the barcode starts and ends, simplifying the decoding process.

## Example of How to Read a Barcode

Let's apply the process of how to read barcode numbers for a product called "QuantumTech Smartwatch.”

### Step 1: Understand the Barcode Basics

Recognize that the 12-digit number "012345678911" corresponds to QuantumTech Smartwatch's UPC-A barcode.

### Step 2: Decode the Numbers

Understand that the first digit "0" corresponds to a narrow white bar.

### Step 3: Use Online Barcode Decoding Tools

Input "012345678911" into Barcode Lookup or a similar tool to get detailed information about QuantumTech Smartwatch.

### Step 4: Mobile Apps for Barcode Decoding

Scan the UPC-A barcode using the Barcode Scanner app on your Android device or Barcode Reader on your iOS device. The app will provide immediate information about QuantumTech Smartwatch.

### Step 5: Understand Check Digits

Verify the check digit "1" in the barcode.

Now, let's calculate the check digit for the first 11 digits "01234567891" of this UPC-A barcode using the steps provided earlier:

Step 1: Add the Digits in Odd Positions (1st, 3rd, 5th, 7th, 9th, and 11th):

0+2+4+6+8+1=21

Step 2: Multiply the Result by 3:

21×3=63

Step 3: Add the Digits in Even Positions (2nd, 4th, 6th, and 8th):

1+3+5+7=16

Step 4: Add the Results from Step 2 and Step 3:

63+16=79

Step 5: Find the Modulus 10:

79 mod  10=9

Step 6: Subtract from 10 to Get the Correct Check Digit:

10−9=1

Therefore, the correct check digit for the first 11 digits "01234567891" of the UPC-A barcode for the product "QuantumTech Smartwatch" is 1.

### Step 6: Utilize Excel or Google Sheets

In Excel or Google Sheets, create a table with digits 0 to 9 and their corresponding bar representations. Enter the barcode "012345678911" to decode and reveal QuantumTech Smartwatch details.

Example:

### Step 7: Learn Morse Code Method

Translate the barcode representation into Morse code. For example, a thick black bar represents a dash, and a thin white bar represents a dot. Decode the entire barcode to reveal QuantumTech Smartwatch information.

Barcode: 012345678911

• 0 (||:::): A (. -)
• 1 (X...): B (- . . .)
• 2 (.XX..): C (- . - .)
• 3 (.XXX.): D (- . .)
• 4 (.X..): E (.)
• 5 (.X...): F (. . - .)
• 6 (.XX.): G (- - .)
• 7 (.XX..): H (. . . .)
• 8 (.XXX.): I (. .)
• 9 (.XX.): J (. - - -)
• 1 (XXXX.): B (- . . .)
• 1 (.X...): B (- . . .)

Decoded Message:
By combining the Morse code symbols, we get the decoded message: ABC DEF GHI JBB.

### Step 8: Understand Quiet Zones and Start/Stop Characters

Identify the quiet zones and start/stop characters in the UPC-A barcode "012345678911." Recognizing these elements helps pinpoint where the barcode starts and ends, facilitating the decoding process for QuantumTech Smartwatch.

We hope that our article has now left you with a better understanding of the process on how to read barcodes.