Digit Sum Calculator

Add up the digits of a number.

Digit sum 15

Digital root 6

Formula: add all digits; repeat for the digital root

Step-by-step with your numbers:

1. Values used:

2. Number = 12,345

4. Digit sum = 15

5. Digital root = 6

Did we solve your problem today?

Sum a number's digits (and reduce to a single-digit root).

The math behind it

Add each digit. The digital root repeats this until one digit remains (equals n mod 9, with 9 for multiples of 9).

12345 → 1+2+3+4+5 = 15, root 6.

Use?

Divisibility checks (by 3 or 9) and checksum tricks.