A UPC (Universal Product Code) is a way for stores to easily scan and track items for sale. They allow cashiers to scan items, rather than having to memorize the price of each item in the store and manually entering it into the cash register when customers check out. The last digit of each UPC is its check digit, which is found using a simple formula. The check digit helps identify errors that occur when entering the UPC. You can find a check digit by looking at the initial 11 numbers on a UPC.
Add together every other digit, starting with the first (small) digit on the left. This means you will add together the first, third, fifth, seventh, ninth and eleventh digits.
Multiply the sum by three.
Add together the digits you didn't add in Step 1. This means you'll add the second, fourth, sixth, eighth and tenth digits.
Add together the totals from Steps 2 and 3.
Find the number that, when added, will make the sum from Step 4 end in a zero. For instance, if your total was 134, the number you'll find is 6. If your total was 115, the number you'll find is 5. If your total is 120, your number is 0. This number is the check digit for the UPC.
- Photo Credit barcode_02 image by Perth from Fotolia.com
- How to Apply for a UPC Number
- How to Find UPC Bar Codes
How to Calculate Check Digit
The check digit is the last number on the bar codes often used in retail for inventory and tracking purposes. The numbers...
- How to Create UPC Codes for Free
- How to Decode a UPC Number
How to Find a UPC
A UPC, or Universal Product Code, is a method of keeping inventory for retail merchandisers. This is often in the form of...
How to Calculate Fixture Units by Plumbing Code
Installing piping in a remodel or a new house requires some math skills, soldering ability, some knee pads and a little knowledge...