Digital Root Calculator
Math
Calculate digital root with explicit inputs and a worked example.
Formula
dr(0)=0; dr(n)=1+((n−1) mod 9) for n>0
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
Example Calculation
Example inputs
- Nonnegative integer: 9875
9+8+7+5=29, then 2+9=11, then 1+1=2.
Frequently asked questions
How do I use this calculator?
Enter nonnegative integer. The result updates automatically. Use Reset to restore the example values.
What method does it use?
dr(0)=0; dr(n)=1+((n−1) mod 9) for n>0. Follow the units and definitions shown with the inputs to apply this relationship consistently.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.