Square Root & Power Calculator
Calculate the square root of a number, or calculate what a number raised to a given exponent equals.
How to use the calculator
- Choose whether to calculate a square root or a power using the buttons above the calculator.
- Enter your number (or base and exponent for power) — the calculator computes the answer automatically as you type.
- Read the explanation below to understand how the answer was calculated.
What is a square root and a power?
The square root of a number is the number that, multiplied by itself, gives the original number. The square root of 144 is 12, because 12 × 12 = 144. A number whose square root is a whole number (like 144) is called a perfect square.
Power tells you how many times a number (the base) should be multiplied by itself. 2^10 means 2 multiplied by itself 10 times, which gives 1,024.
If the exponent is negative, it means dividing instead of multiplying. For example, 2^-3 = 1 ÷ 2³ = 1 ÷ 8 = 0.125.
Frequently asked questions
What is a square root?
The square root of a number is the number that, multiplied by itself, gives the original number. The square root of 25 is 5, because 5 × 5 = 25. Negative numbers have no real square root.
What happens with powers that have a negative exponent?
A negative exponent turns the expression into a fraction: a^-n = 1 ÷ a^n. For example, 2^-3 equals 1 ÷ 8, or 0.125.
Why do some square roots become "ugly" decimals?
Only perfect squares (like 4, 9, 16, 25 …) have whole numbers as their square root. All other numbers get a square root with infinitely many decimals, which is rounded when displayed.