Root and Power Calculator

1. 01Pick root or power modeChoose "Root" to find a square root or nth root, or "Power" to raise a number to an exponent.
2. 02Enter the numbersFor a root: enter the number and the root degree (2 for square root, 3 for cube root, and so on). For a power: enter the base number and the exponent.
3. 03Read the resultThe result appears automatically as you type.

• Checking math homeworkQuickly compute and verify a square root, cube root, or a number raised to a power.
• Finding other nth rootsBeyond square and cube roots, calculate any nth root (for example, a 4th or 5th root) by changing the root degree.
• Calculating negative or fractional exponentsCompute a number raised to a negative exponent (the result is a fraction) or a fractional exponent (equivalent to a root).

• Square root of 16The square root (degree 2) of 16 is 4.
• Cube root of a negative numberThe cube root (degree 3) of -8 is -2, because (-2)³ = -8.
• 2 to the power of 102 raised to the 10th power is 1,024.

The nth root of x is calculated as x^(1/n). For negative numbers, a root only has a real result when the degree is odd (cube root, fifth root, and so on) — an even root (square root, 4th root, and so on) of a negative number has no real result, because no real number raised to an even power produces a negative number. A power is calculated directly as the base raised to the exponent, including negative exponents (the result is a fraction, 1/base^|exponent|) and fractional exponents (equivalent to a root).

Root mode: you enter the number and its root degree. Power mode: you enter the base number and its exponent. Results are shown to 6 decimal places for non-whole-number results.

A common mistake is trying to calculate an even root (square root, and so on) of a negative number, which has no real result — this calculator shows a message that no result exists, rather than an incorrect number. Very large power results (for example, 10 to the power of 1000), and very large root results (for example, a very small root degree applied to a large number), are also not shown, since they exceed the range that can be represented accurately.

The calculation runs in your browser. The numbers you enter are never uploaded, stored, or shared, and closing the tab clears everything.

Why can I not calculate the square root of a negative number?

Because no real number multiplied by itself produces a negative number. A result like this is called an imaginary number, which is outside the scope of this calculator.

Can it calculate the cube root of a negative number?

Yes. The cube root (and other odd roots) of a negative number has a real result that is also negative — for example, the cube root of -8 is -2.

What is a fractional exponent?

A fractional exponent is equivalent to a root. For example, raising a number to the power of 0.5 is the same as taking its square root, and raising it to the power of 1/3 is the same as taking its cube root.

What does a negative exponent give?

A negative exponent produces a fraction: a number raised to the power of -n equals 1 divided by that number raised to the power of n. For example, 2 to the power of -2 = 1/(2²) = 0.25.

Is my data saved?

No. Everything is calculated in your browser; nothing is sent to a server.