Calculate Digit Sum

The digit sum is the sum of the ciphers of a number. To calculate, just type or paste any text with numbers into the field and press Calculate digit sums. Characters, which aren't numbers, are counted, but ignored for the digit sums. For the alternating digit sum, the numbers are alternatingly added and subtracted: z1-z2+z3-z4+z5-... . For the iterated digit sum, the digit sum is executed until the result is one-digit.

Digit sum: Alternating digit sum:

Iterated digit sum: Iterations:

Amount of digits: Amount of characters:

Example: the digit sum of 1234 = 1+2+3+4 = 10

If a number is divisible without remainder by 3 or 9, then the same is true for its digit sum and vice versa. Digit sums are used for instance as digit sums for number values.

The digit sum can be formed by any natural number. It is the sum of the individual digits. There are variants of the digit sum:
The iterated digit sum, which can also be determined with this calculator, takes the digit sum one after the other until a single-digit value is reached. So there are only 9 options for it. Alternating means alternating plus and minus.
The digit sum below a value continues until the digit sum falls below a certain value greater than or equal to 9.
Base k-digit sum means a digit sum over more than one digit. It can also be alternating.
The weighted digit sum assigns each digit a weight by which it is multiplied.
With a digit product, the individual digits are multiplied instead of added; this can also be iterated. The disadvantage of the digit product is that a zero in the number immediately produces a zero as the final result. For example, it can be used where only single-digit numbers without 0 appear.
Finally, the triangular numbers only have a remote connection with the digit sum; here, successive natural numbers are added together.