IMEI check digit calculator
Enter the first 14 digits of an IMEI to calculate its check digit. Every doubling and sum is shown, so you can follow the Luhn algorithm or verify it by hand.
Enter 14 digits. If you enter all 15, the last one is compared with the calculated check digit.
Worked example
For the commonly cited example 49015420323751, the calculation is:
So the complete IMEI is 490154203237518.
The rule in one sentence
Starting from the rightmost of the 14 digits, double every other digit, add up the digits of all the results, and choose the check digit that makes the total a multiple of 10.
Questions
Why does an IMEI need a check digit?
To catch errors when people read or type the number. A single wrong digit, or most swaps of two neighbouring digits, changes the expected check digit, so the mistake shows up straight away.
Is the check digit transmitted to the network?
No. Under 3GPP TS 23.003 the check digit is not transmitted over the air. Networks receive the 14-digit body, or the IMEISV with its software version instead. The check digit is printed on labels and shown by *#06#.
Can I use this to create an IMEI?
The calculator completes a number you already have. Changing a device’s IMEI is illegal in many countries. Generating IMEIs to impersonate devices is not something this site supports.