Square Root & Exponent Calculator

Square Root & Exponent Calculator

Square Root (√x)
Cube Root (∛x)
Nth Root
Nth Power
x² (Squared)
x³ (Cubed)

Perfect Squares Reference (1–20)

n√(n²) = n

Square Root Calculator – √ and Exponent Guide

This free online square root calculator instantly finds the square root, cube root, Nth root, and Nth power of any number. Enter a number, optionally specify N for custom root or power calculations, and get all six results at once. A perfect squares reference table is included on the page for quick lookup.

What Is a Square Root?

The square root of a number x is the value that, when multiplied by itself, gives x. Written as √x, it is the inverse operation of squaring. For example, √144 = 12 because 12 × 12 = 144. Every positive number has two square roots — a positive and a negative — but by convention, the principal (positive) square root is what calculators return.

Square roots of negative numbers are not real numbers. In the complex number system they involve the imaginary unit i, but this calculator works in the real number domain only.

Cube Roots and Nth Roots

The cube root (∛x) is the number that, multiplied by itself three times, equals x. Unlike square roots, cube roots are defined for negative numbers: ∛(−8) = −2. The general Nth root of x equals x^(1/N). This calculator supports any positive integer N you enter.

Perfect Squares

A perfect square is any integer that is the square of another integer. The first ten are: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100. Recognizing perfect squares speeds up mental arithmetic and is useful in simplifying radical expressions. A full reference table for 1 through 20 is included in the tool above.

Applications of Square Roots

  • Geometry: Finding the side length of a square from its area (side = √area).
  • Physics: Velocity calculations in kinetic energy formulas (v = √(2E/m)).
  • Statistics: Standard deviation involves a square root.
  • Engineering: RMS (root mean square) voltage and signal processing.
  • Finance: Compound interest period calculations use Nth roots.

Frequently Asked Questions

Can I find the square root of a negative number?
In real number mathematics, square roots of negative numbers are undefined. The calculator will display "Not real." For cube roots and other odd-order roots, negative inputs are supported.
How do I calculate the 5th root of a number?
Enter the number in the "Number" field and enter 5 in the "N" field, then click Calculate. The Nth Root result will show the 5th root.
What is the difference between √x and x²?
√x (square root) asks "what number squared gives x?" while x² (squaring) multiplies x by itself. They are inverse operations: √(x²) = x for any non-negative x.
Why is √2 irrational?
√2 cannot be expressed as a ratio of two integers. Its decimal expansion (≈1.41421356…) continues infinitely without repeating. This was famously proved by ancient Greek mathematicians.
How accurate are the results?
Results are computed using JavaScript's native Math functions (IEEE 754 double precision) and rounded to 10 decimal places, giving accuracy to 10 significant figures for most inputs.