Square Root Calculator
Enter a number to calculate its square root, square, and cube root.
Last updated: September 5, 2026
Frequently asked questions
What's the square root of 144?
12 - since 12 × 12 = 144, making 144 a perfect square.
Why don't negative numbers have a real square root?
Any real number squared is positive (or zero), so no real number multiplied by itself can produce a negative result - negative square roots require imaginary numbers.
How do I estimate a square root without a calculator?
Find the two perfect squares your number falls between, then interpolate. For √50, it's between √49=7 and √64=8, closer to 7, so a reasonable estimate is about 7.07 - which matches the exact value.
What's the difference between a square root and a cube root?
A square root asks what number times itself equals the input; a cube root asks what number times itself three times equals the input. The square root of 27 isn't a whole number, but the cube root of 27 is exactly 3, since 3 x 3 x 3 = 27.
What's the cube root of a negative number, like -8?
-2, since -2 × -2 × -2 = -8 - unlike square roots, cube roots of negative numbers are real, because multiplying three negative numbers together gives a negative result.
What is the square root of 0?
0 - since 0 × 0 = 0, and it's the only number whose square root, square, and cube root are all equal to itself.
Is 'square root' the same as 'radical' or the '√ symbol'?
Yes - '√', 'radical', and 'square root' all refer to the same operation of finding a number that, multiplied by itself, produces the value under the symbol.