Sum the digits of a whole number and see the breakdown instantly.
Last updated: June 2026 | By Patchworkr Team
The digit sum of a whole number is the total you get by adding all of its digits once.
The digit sum is 30.
Does the calculator accept decimals?
No. A digit sum is defined for whole numbers, so decimals are rejected instead of being guessed.
What about a minus sign?
A leading minus sign is ignored and only the digits are added.
Can I enter blank input?
Blank input is treated as invalid so the calculator does not invent a value.
Is the digit sum the same as the digital root?
No. Digit sum adds the digits once, while digital root repeats the process until one digit remains.