← math calculators
Cube Root Calculator
Find the cube root of any number, including negatives
About this calculator
The cube root of n is the value that, when multiplied by itself three times, gives n. Written as ∛n. For example, ∛27 = 3 because 3 × 3 × 3 = 27. Unlike square roots, cube roots work for negative numbers: ∛(−8) = −2. Cube roots appear in volume calculations — if a cube has volume 125 m³, each side is ∛125 = 5 m.
How to use
Enter any number, positive or negative. ∛(−64) = −4 because (−4)³ = −64.
Frequently asked questions
Why can cube roots be negative when square roots cannot?
Because a negative number cubed stays negative: (−3)³ = −27. But a negative number squared becomes positive: (−3)² = 9. So there is no real square root of a negative number, but cube roots of negative numbers are real.