Most calculators have a square root button labeled √ or a menu option for it

The square root button is usually marked with the √ symbol on your calculator's face. On basic calculators, it's often a dedicated button you press directly. On scientific calculators and graphing calculators, you may need to press a shift or function key first to access it, or find it in a menu. The exact location depends on your calculator model, so checking your manual or the calculator's case for a quick reference is the fastest way to find it.

Once you locate the button, the process is straightforward: enter the number you want the square root of, then press the square root button. The calculator displays the result immediately. For example, if you enter 16 and press √, you get 4.

Key Takeaways

  • The square root button is labeled √ on most calculators and is either a standalone button or accessed through a shift or function key.
  • On basic calculators, you enter the number first, then press √; on some scientific calculators, you press √ first, then enter the number.
  • If your calculator doesn't have a dedicated square root button, you can use the exponent function to calculate it by raising the number to the power of 0.5.
  • The square root of a number is the value that, when multiplied by itself, equals that number — for example, the square root of 25 is 5 because 5 × 5 = 25.

Finding the square root button on different calculator types

Basic calculators usually have the √ button printed directly on the face, often in the top rows near other math functions. Press your number, then press √. Some basic models require you to press √ first, then the number — your manual will clarify which order your model uses.

Scientific calculators typically have √ on the main keypad, but you may need to press a Shift key (sometimes labeled 2nd or Inv) to access it. Look for the √ symbol printed above a button in smaller text; that's the shifted function. Press Shift, then the button with √ above it, then your number.

Graphing calculators like the TI-84 have the square root function in a menu. Press the Math button, scroll to find the square root option (usually near the top of the list), select it, then enter your number and press Enter.

Phone calculators vary by device. On most smartphones, open the calculator app and look for a √ button or a menu (often three dots or lines). Some phone calculators hide the square root function until you rotate your phone to landscape mode or tap a "scientific" or "more" option.

The order matters: when to enter the number first

On most modern calculators, you enter the number first, then press the square root button. This is the standard on basic calculators, scientific calculators with Shift access, and graphing calculators. For example: type 49, press √, get 7.

Some older or simpler calculators work the opposite way — you press √ first, then type the number. If you try the standard order and get an error or unexpected result, try reversing it. Your calculator's manual or a quick online search for your specific model will confirm which method yours uses.

If you're unsure, test with a number you know the answer to. The square root of 4 is 2, the square root of 9 is 3, and the square root of 100 is 10. Try both orders with one of these numbers to see which gives you the right answer.

Using the exponent function if your calculator has no square root button

If your calculator doesn't have a dedicated square root button, you can calculate a square root using the exponent or power function, usually labeled ^ or x^y. The trick is that the square root of any number is the same as raising that number to the power of 0.5.

To do this: enter your number, press the exponent button, enter 0.5, then press equals. For example, to find the square root of 36, you would type: 36, press ^, type 0.5, press =, and get 6. This works on any calculator with an exponent function, including phone calculators and spreadsheet programs.

Understanding what a square root actually is

A square root is the number that, when multiplied by itself, gives you the original number. For example, 5 is the square root of 25 because 5 × 5 = 25. The square root of 16 is 4 because 4 × 4 = 16. Every positive number has a square root, and most square roots are not whole numbers — the square root of 10 is approximately 3.162.

The √ symbol is just shorthand for "find the number that multiplies by itself to make this." When you press the square root button, the calculator does the math instantly instead of you having to guess and check.

Common mistakes and how to avoid them

The most common mistake is pressing buttons in the wrong order. If you get an error message or a result that seems way too large or too small, try reversing the order — press √ first, then the number, or vice versa depending on what you tried.

Another mistake is trying to find the square root of a negative number on a basic calculator. Basic calculators cannot calculate square roots of negative numbers and will show an error. Scientific and graphing calculators can handle this, but they display the result using imaginary numbers, which is beyond basic use.

If your result looks odd — for example, the square root of 2 shows as 1.41421356 instead of a clean number — that's correct. Most square roots are not whole numbers, and your calculator is showing you the decimal version. This is normal and expected.

Frequently Asked Questions

What if my calculator shows an error when I press the square root button?

First, check that you entered a positive number. Basic calculators cannot find square roots of negative numbers. If your number is positive, try reversing the order — enter the number first if you pressed √ first, or vice versa. If that doesn't work, your calculator may not have a square root function, and you should use the exponent method instead (raise the number to the power of 0.5).

Why does the square root of 2 give me a long decimal instead of a whole number?

Because the square root of 2 is not a whole number. It's approximately 1.414, and the calculator is showing you the decimal version. Most square roots are not whole numbers — only perfect squares like 4, 9, 16, 25, and 100 have whole number square roots. This is normal and correct.

Can I find a square root on my phone's calculator?

Yes. On most phones, open the calculator app and look for a √ button or tap a menu option (often labeled "scientific" or shown as three dots). On some phones, you need to rotate your phone to landscape mode to see more functions. If your phone calculator doesn't show a square root button, use the exponent method: enter the number, press the power button (^), type 0.5, and press equals.

Is there a difference between square root and squaring a number?

Yes. Squaring means multiplying a number by itself (5 × 5 = 25). The square root is the opposite — it finds the number that was multiplied by itself (the square root of 25 is 5). On a calculator, squaring is usually a button labeled x² or found through a shift function, while square root is √.