What is a cube root?
A number y such that y³ equals x.
Cube Root Calculator
Find ∛x, the real number y such that y³ = x.
Enter a number
Provide any real value x (positive, negative, or zero).
About this calculator
How to use Cube Root Calculator, plus the formulas and logic behind the results.
Tool description
Every real number has one real cube root. Negative inputs yield negative outputs.
How to use
- Enter x.
- Select Calculate.
- Read ∛x.
- Optionally verify by cubing the result.
Formulas & reference
y = ∛xy³ = x
Examples
- ∛27 = 3
- ∛8 = 2
- ∛(−8) = −2
- ∛0 = 0
Calculation logic
Uses PHP pow with exponent 1/3, with a sign-safe approach for negative bases.
Complex cube roots are not listed—only the principal real root.
Cube Root Calculator FAQ
Common questions about this calculator and how to use the results.
Can x be negative?
Yes. The real cube root is negative.
Is ∛x the same as x^(1/3)?
For real numbers, yes with careful handling of negatives.
Are there three cube roots?
Over complex numbers yes; this tool returns the real one.
What is ∛1?
1.
How do I check?
Cube the result and compare with x.