Parking
Free street parking directly on Livernois outside the shop, and on the side streets off Fenkell. You will not be circling the block.
Calculator
IMEI check digit
IMEI check digit
calculator.
The last digit of an IMEI is a checksum of the other fourteen. Enter 14 digits to work it out, or 15 to verify one.
How it works
The Luhn formula.
Take the first fourteen digits. Double every second one counting from the right, and if doubling takes a digit above nine, subtract nine. Add all fourteen results together. The check digit is whatever takes that total up to the next multiple of ten.
It exists so a mistyped number is caught rather than quietly looked up as somebody else's phone. The same formula validates bank cards. It is arithmetic, not a database — which is why nobody should ever charge you for it.
Worked example
49015420323751 → 8.
- Write the fourteen digits: 4 9 0 1 5 4 2 0 3 2 3 7 5 1.
- Counting from the right, double every second digit: 1→2, 7→14, 2→4, 0→0, 4→8, 1→2, 9→18.
- Anything above nine, subtract nine: 14→5, 18→9.
- Add everything up — the doubled digits and the untouched ones: 4+9+0+2+5+8+2+0+3+4+3+5+5+2 = 52.
- The next multiple of ten is 60. The check digit is 60 − 52 = 8. Full IMEI: 490154203237518.
Where it trips people up
Fourteen, fifteen or sixteen digits.
- Fourteen on the box, fifteen on the screen — some labels print the IMEI without its check digit. Both refer to the same phone; this page adds the fifteenth for you.
- Sixteen digits is an IMEISV: the same fourteen followed by a two-digit software version, with no check digit at all. Drop the last two and you have the IMEI without its check digit.
- A valid check digit is not proof of a real phone. It only proves the number was typed correctly. Whether those digits were ever assigned to a handset is what the free checker answers.