The cube root of a number is a value that, when multiplied by itself three times, gives the original number. The cube root of 27 is 3 because 3 x 3 x 3 = 27. Unlike square roots, cube roots exist for negative numbers: the cube root of -8 is -2 because (-2) x (-2) x (-2) = -8. Cube roots appear in volume calculations (finding the side length of a cube given its volume), physics, and engineering applications where three-dimensional relationships are involved.
This calculator also computes nth roots for any positive integer n. The nth root of x is written as x^(1/n). The 4th root of 16 is 2, the 5th root of 32 is 2, and so on. Higher roots converge toward 1 as n increases. Nth roots are used in compound interest calculations (finding the rate), geometric means in statistics, and signal processing.
Enter the number you want to find the root of, and specify the root index (3 for cube root, or any other value for nth root). Click Calculate to see the result with up to 10 decimal places. The calculator indicates whether the result is a perfect root (integer) and shows the verification (result^n = original number).
Yes. Unlike square roots, cube roots of negative numbers are real. The cube root of -27 is -3 because (-3)^3 = -27. All odd-numbered roots of negative numbers are real.
Numbers whose cube root is an integer: 1, 8, 27, 64, 125, 216, 343, 512, 729, 1000 are the first ten perfect cubes.
Cube root is the same as raising to the power of 1/3. So cbrt(x) = x^(1/3). Similarly, nth root is x^(1/n). This relationship is how calculators compute roots internally.