Calculate cube roots instantly with our free online calculator. Find perfect cubes, simplify radical expressions, and see precise results. Pure client-side, no ads.
The cube root of a number is a value that, when multiplied by itself three times, gives the original number. For example, the cube root of 27 is 3 because 3 × 3 × 3 = 27. Unlike square roots, cube roots can be calculated for negative numbers (e.g., ∛−8 = −2). This calculator handles all real numbers, identifies perfect cubes, simplifies radical expressions, and provides precise decimal approximations. All calculations happen instantly in your browser.
The cube root of a number x is a number y such that y³ = x. For example, ∛64 = 4 because 4³ = 64. Every real number has exactly one real cube root, including negative numbers.
A perfect cube is a number that is the cube of an integer. Examples include 1, 8, 27, 64, 125, 216, 343, 512, 729, 1000, and so on. The cube root of a perfect cube is always an integer.
Yes! Unlike square roots, cube roots of negative numbers are real. For example, ∛−8 = −2 because (−2)³ = −8. This is because multiplying three negative numbers together gives a negative result.
The calculator finds the largest perfect cube factor of the input number and factors it out. For example, ∛54 = ∛(27 × 2) = ∛27 × ∛2 = 3∛2. This is the simplified radical form.
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