Nth Root Calculator

Calculate any nth root of a number including square root, cube root, and custom roots.

What Is the Nth Root Calculator?

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

ⁿ√x = x^(1/n) | For negative x with odd n: ⁿ√x = −(ⁿ√|x|)

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

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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