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Calculators/Maths/Digital root
Maths

Digital root calculator

Repeatedly sums the digits of a number until one digit remains.

What this calculator does

Digital root works out repeatedly sums the digits of a number until one digit remains. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.

The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.

The formula

FormulaFor n > 0: digital root = 1 + (n − 1) mod 9 (0 stays 0)

The inputs explained

FieldWhat to enter
Whole numberA number. Starts at 493193.

Worked examples

Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.

How the answer changes with whole number

Every other input is held at the calculator’s starting values while whole number varies. Select any row to load that scenario into the calculator.

How the answer changes with whole number
Whole numberDigital rootStepsNumber of steps
246,5976246597 → 33 → 62
369,8954369895 → 40 → 42
493,1932493193 → 29 → 11 → 23
739,7908739790 → 35 → 82
986,3864986386 → 40 → 42
1,479,57961479579 → 42 → 62