Check digit calculator
To calculate the check digit for the new ISBN13 see below.
UPCA/UPCE (zero suppression) convertor
Check digit calculation explained
To calculate the check digit of an UCC12 (UPCA) with number 0 12345 12345 follow the following five steps.
Step one: From the right to the left, start with odd
position, assign the odd/even position to each digit.
Index 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
Digit 
0 
1 
2 
3 
4 
5 
1 
2 
3 
4 
5 
Position 
odd 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
Step two: add all digits in odd position and multiply the result by 3: (0+2+4+1+3+5)*3=45
Step three: add all digits in even position: (1+3+5+2+4)=15
Step four: add the results of step three and four: 45+15=60
Step five: substract the sum from the next highest multiple of ten, the result is the check digit. (If the result is 10 then the check digit is 0): 7060=10, so the check digit is 0.
To calculate the check digit of an UCC13 (EAN13) with number 87 12345 12345 follow the following five steps.
Step one: from the right to left, start with odd position, assign the odd/even position to each digit.
Index 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
Digit 
8 
7 
1 
2 
3 
4 
5 
1 
2 
3 
4 
5 
Position 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
Step two: add all digits in odd position and multiply the result by 3: (7+2+4+1+3+5)*3=66
Step three: add all digits in even position. (8+1+3+5+2+4)=23
Step four: add the results of step three and four: 66+23=89
Step five: substract the sum from the next highest multiple of ten, the result is the check digit. (If the result is 10 then the check digit is 0): 9089=, so the check digit is 1.
To calculate the check digit of an EAN/UCC14 (EAN14) with number 1 87 12345 12345 follow the following five steps.
Step one: from the right to left, start with odd position, assign the odd/even position to each digit.
Index 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
Digit 
1 
8 
7 
1 
2 
3 
4 
5 
1 
2 
3 
4 
5 
Position 
odd 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
Step two: add all digits in odd position and multiply the result by 3: (1+7+2+4+1+3+5)*3=69
Step three: add all digits in even position: (8+1+3+5+2+4)=23
Step four: add the results of step three and four: 69+23=92
Step five: substract the sum from the next highest multiple of ten, the result is the check digit. (If the result is 10 then the check digit is 0): 10092=8, so the check digit is 8.
To calculate the check digit of an SSCC with number 12 345678901234567 follow the following five steps.
Step one: from the right to left, start with odd position, assign the odd/even position to each digit.
Index 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 
Digit 
1 
2 
3 
4 
5 
6 
7 
8 
9 
0 
1 
2 
3 
4 
5 
6 
7 
Position 
odd 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
Step two: add all digits in odd position and multiply the result by 3: (1+3+5+7+9+1+3+5+7)*3=123
Step three: add all digits in even position: (2+4+6+8+0+2+4+6)=32
Step four: add the results of step three and four: 123+32=155
Step five: substract the sum from the next highest multiple of ten, the result is the check digit. (If the result is 10 then the check digit is 0): 160155=5, so the check digit is 5.
To calculate the check digit of an EAN/UCC8 with number 87 12345 follow the following five steps.
Step one: From the right to left, start with odd position, assign
the odd/even position to each digit.
Index 
1 
2 
3 
4 
5 
6 
7 
Digit 
8 
7 
1 
2 
3 
4 
5 
Position 
odd 
even 
odd 
even 
odd 
even 
odd 
Step two: add all digits in odd position and multiply the result by 3: (8+1+3+5)*3=51
Step three: add all digits in even position: (7+2+4)=13
Step four: add the results of step three and four: 51+13=64
Step five: substract the sum from the next highest multiple of ten, the result is the check digit. (If the result is 10 then the check digit is 0): 7064=6, so the check digit is 6.
To calculate the check digit of an ISBN or ISSN with number 012345678 follow the following five steps.
Step one: arrange the 9digit ISBN number in a table. Starting from the left, fill in the weight row with number from 10 to 2.
index 
1 
2 
3 
4 
5 
6 
7 
8 
9 
digit 
0 
1 
2 
3 
4 
5 
6 
7 
8 
weight 
10 
9 
8 
7 
6 
5 
4 
3 
2 
Step two: multiply each digit with its weight and sum the results of multiplication: 0*10+1*9+2*8+3*7+4*6+5*5+6*4+7*3+8*2=156
Step three: divide the sum by modulus 11 and get the remainder: 156:11=14.2, remainder is 2
Step four: the check digit is the number that adds the remainder to 11. (If the result is 10, then check digit is the character X) 2+9= 11 The check digit is 9.
Step five: generate the complete ISBN with hyphens: 0123456789.
The method to calculate the checkdigit of an ISBN13 is identical to the method for an EAN/UCC13 (EAN13). To calculate the check digit of an ISBN13 with number 978012345678 follow the following five steps.
Step one: from the right to left, start with odd position, assign the odd/even position to each digit.
Index 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
Digit 
9 
7 
8 
0 
1 
2 
3 
4 
5 
6 
7 
8 
Position 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
even 
odd 
Step two: add all digits in odd position and multiply the result by 3: (7+0+2+4+6+8)*3=81
Step three: add all digits in even position. (9+8+1+3+5+7)=33
Step four: add the results of step three and four: 81+33=114
Step five: substract the sum from the next highest multiple of ten, the result is the check digit. (If the result is 10 then the check digit is 0): 120114=6, so the check digit is 6.
