Nth Root Calculator — Square & Cube
Calculate any nth root of a number including square root, cube root, and custom roots.
What Is the Nth Root Calculator — Square & Cube?
The Nth Root Calculator computes the nth root of any number — including square roots (n=2), cube roots (n=3), and any higher-order root. It solves equations of the form xⁿ = a for x, and handles both positive and negative radicands for odd roots.
Formula
How to Use
Enter the number you want to find the root of (the radicand) and the root degree n. For a square root, enter n=2. For a cube root, enter n=3. The calculator returns the principal nth root and displays it as a decimal rounded to 10 significant figures.
Example Calculation
4th root of 625: ⁴√625 = 625^(1/4) = (5⁴)^(1/4) = 5. Cube root of −27: ³√(−27) = −(³√27) = −3. 5th root of 32: ⁵√32 = 32^(1/5) = 2, because 2⁵ = 32.
Understanding Nth Root — Square & Cube
The nth root of a number x is the value that, when raised to the power n, gives x. It is the inverse operation of exponentiation: if yⁿ = x, then y = ⁿ√x = x^(1/n). While square and cube roots are the most commonly needed, higher-order roots appear in signal processing, physics, statistics, and financial mathematics.
For positive radicands, any positive integer root exists as a real number. For negative radicands, only odd roots exist in the real number system — e.g., the cube root of −8 is −2. Even roots of negative numbers (like √(−4)) require complex numbers and are not computed by this tool.
Practical applications of nth roots include finding the geometric mean (nth root of a product of n numbers), computing compound growth rates (nth root of cumulative return), solving polynomial equations, and working with logarithmic scales. The calculator handles fractional n as well, computing arbitrary power roots.
Frequently Asked Questions
Can I calculate the square root using this tool?
Yes. The square root is the 2nd root. Enter n=2 to compute √x.
Why can't I take an even root of a negative number?
Even roots of negative numbers are not real — they are complex numbers (involving i = √(−1)). This calculator returns real results only.
What is the cube root used for?
Cube roots arise in volume calculations (finding the side of a cube from its volume), physics equations, and solving depressed cubic equations.
How accurate are the results?
Results are accurate to at least 10 significant figures using floating-point arithmetic. For perfect roots (e.g., ³√8 = 2), the result is exact.
Is this calculator free?
Yes, completely free with no sign-up or registration.
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