Math

Digital Root Calculator

Iterated digit sum of a non-negative integer.

Free to use — no sign-up or login.

Digital root

Digit sum

This free Digital Root Calculator covers Iterated digit sum of a non-negative integer.

The digital root is n mod 9, except multiples of 9 (nonzero) become 9. Related math tools sit beside How it works, with no account required.

Using the Digital Root Calculator

Iterated digit sum of a non-negative integer. Typical inputs are n. How it works beside the form states the identity the Digital Root Calculator applies.

FAQ

How do I use the Digital Root Calculator?

Open the Digital Root Calculator, fill n, and read the result. The digital root is n mod 9, except multiples of 9 (nonzero) become 9.

What formula does the Digital Root Calculator use?

The Digital Root Calculator uses the identity in How it works. In words: The digital root is n mod 9, except multiples of 9 (nonzero) become 9.