The square root button is usually marked with a √ symbol or the word "sqrt"
Most calculators have a dedicated square root function. On basic calculators, look for a button labeled √ or sqrt. On scientific calculators, you may need to press a shift or 2nd button first to access it. On your phone's calculator app, you might need to rotate the screen to landscape mode to see the √ button appear.
The square root of a number is straightforward the value that, when multiplied by itself, gives you the original number. For example, the square root of 9 is 3, because 3 × 3 = 9. You do not need to understand the math behind it to use the button — you just need to know which one to press.
Key Takeaways
- The square root button is marked with √ or the word "sqrt" on most calculators.
- On scientific calculators, you usually enter the number first, then press the √ button.
- On phone calculators, rotate your screen to landscape mode to see the √ button.
- If your calculator does not have a √ button, you can use the power function to find the square root by raising the number to the 0.5 power.
How to use the square root button on a basic calculator
On a standard calculator, the process is straightforward. Type the number you want to find the square root of, then press the √ button. The answer appears on the screen when ready. For example, if you want the square root of 16, type 16, then press √, and the calculator shows 4.
Some older calculators work in reverse order — you press the √ button first, then type the number. If pressing √ after the number does not work, try pressing it before. Your calculator's manual or a quick test will show you which order yours uses.
Square root on a scientific calculator
Scientific calculators often hide the square root function behind a secondary button. Look for a button labeled shift, 2nd, or inv (for inverse). Press that button, then look for the √ symbol printed above one of the number buttons — that is usually where the square root function lives.
The steps are: type your number, press shift (or 2nd), then press the button with the √ symbol above it. The answer appears on the display. If you cannot find a √ symbol printed on any button, check your calculator's manual — some scientific models use different notation.
Finding square root on your phone's calculator
The calculator app on your phone hides the square root button in landscape mode. Open your calculator, then rotate your phone sideways so the screen is wider. The scientific calculator view appears, and you will see the √ button on the left side of the screen.
Enter your number, then tap the √ button. The answer shows up when ready. If rotating does not reveal more buttons, your phone's calculator may not have a square root function built in — in that case, you can read a scientific calculator app from your phone's app store.
Using the power function if there is no square root button
If your calculator does not have a √ button, you can still find a square root using the power or exponent function. Look for a button marked ^, x^y, or **. The square root of any number is the same as raising that number to the power of 0.5.
Type your number, press the power button, then type 0.5, and press equals. For example, to find the square root of 25, you would type 25, press ^, type 0.5, then press =. The answer is 5. This method works on any calculator that has an exponent function, including spreadsheet programs like Excel.
Common mistakes when using the square root button
The most common error is pressing the button in the wrong order. If you type the number and press √ but nothing happens, try pressing √ before you type the number instead. The second mistake is confusing the square root button with other similar-looking buttons — the x² button does the opposite (it squares a number rather than finding its root), so make sure you are pressing the right one.
Another frequent problem is forgetting that negative numbers do not have square roots in basic math. If you try to find the square root of a negative number on a standard calculator, it will show an error. This is normal and not a sign that your calculator is broken.
Why you might need the square root function
Square roots come up in everyday situations more often than you might think. If you are calculating the side length of a square room based on its area, finding the diagonal of a rectangle, or working through a recipe that scales by area, you will need the square root. In work settings, it appears in statistics, construction measurements, and financial calculations.
You do not need to memorize square roots or understand the deeper math. The button does the work for you — your job is just knowing which button to press and in what order.
Frequently Asked Questions
What is the difference between the √ button and the x² button?
The √ button finds the square root — it tells you what number multiplied by itself gives you the original number. The x² button does the opposite — it squares a number by multiplying it by itself. If you press x² on 3, you get 9. If you press √ on 9, you get 3.
Can I find the square root of a decimal number?
Yes. Type the decimal number and press √ just as you would with a whole number. For example, the square root of 2.25 is 1.5. The calculator handles decimals automatically.
Why does my calculator show a very long decimal when I find a square root?
Many square roots do not come out to whole numbers or straightforward decimals. The square root of 2, for example, is approximately 1.41421356... and goes on forever. Your calculator is showing you the closest answer it can display. You can round it to fewer decimal places if you need a simpler number.
What does it mean if my calculator shows "error" when I press the square root button?
This usually means you tried to find the square root of a negative number, which is not possible in basic math. Check that you typed the correct number. If the number is positive and you still see an error, try pressing the buttons in the opposite order or check your calculator's manual.
Is there a square root button on a computer keyboard?
No, but you can open the calculator app on your computer (search for "calculator" in Windows or "Calculator" on Mac) and use the same method as your phone — switch to scientific view to see the √ button.