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Free Square Root & Nth Root Calculator

Calculate the square root, cube root, or any nth root of a number, with every step shown.

100% Free No Signup Works on all devices

Built and fact-checked by the DocNectar team — see our editorial standards

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Key Features

Instant Calculation

Get accurate results in real time with our optimized algorithm.

Mobile Friendly

Fully responsive design. Works on all devices & screen sizes.

Privacy Focused

Your data stays on your device. We don't store any inputs.

100% Free

No hidden costs. This tool is completely free forever.

A root is the inverse of raising a number to a power — the square root undoes squaring, the cube root undoes cubing, and so on for any degree.

This calculator finds the square root, cube root, or any nth root of a number and shows the full working.

How it works

Enter a number and the root degree (2 for square root, 3 for cube root, or any higher degree). The calculator raises the number to the power of 1/n to find the root, and flags cases where an even-degree root of a negative number has no real result.

  1. Enter number.
  2. Enter root degree (2 = square root, 3 = cube root).
  3. Click Calculate to see your results.

Examples

Finding a square root

The square root of 144 is 12, since 12 × 12 = 144.

Finding a cube root

The cube root of 27 is 3, since 3 × 3 × 3 = 27.

Who should use it

  • Checking a geometry or algebra homework answer.
  • Finding a side length from an area or volume in a construction or design calculation.

Industry applications

  • Mathematics and engineering education
  • Geometry, physics, and construction calculations

Advantages

  • Supports any root degree, not just square and cube roots.
  • Clearly flags when a root has no real result.

Limitations

  • Only returns real number results — does not compute results in the complex number system.

Common mistakes to avoid

  • Assuming every number has a real square root — negative numbers do not.
  • Confusing the root degree with the number itself when entering values.

Best practices

  • Double-check whether you need the positive root only, or both the positive and negative square roots, depending on your context (like solving an equation).

Tips

  • To check any root by hand, raise your answer back to the root degree — it should return the original number.

Frequently asked questions

Yes, with no signup and no limit on how many calculations you run.
No real number multiplied by itself produces a negative result, so an even-degree root (like a square root) of a negative number has no real answer — it requires imaginary numbers, which this calculator doesn't compute.
Yes — odd-degree roots (cube root, 5th root, and so on) of negative numbers are real. For example, the cube root of -8 is -2, since -2 × -2 × -2 = -8.
The calculator returns a decimal approximation rounded to 6 decimal places whenever the exact root isn't a whole number.

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