how to find a square root on a calculator

If you have ever asked, "how to find a square root on a calculator", the good news is that it is one of the easiest calculator functions once you know where the key is and how to enter the number correctly.

In this guide, you will learn the exact button sequence for different calculator types, what to do if your calculator does not have a square root key, and how to avoid common mistakes.

What a square root means (quick refresher)

The square root of a number is a value that, when multiplied by itself, gives the original number.

• √9 = 3 because 3 × 3 = 9
• √64 = 8 because 8 × 8 = 64
• √2 ≈ 1.4142 because it is not a perfect square

On calculators, square root is usually shown as √, sqrt, or as a second function above another button.

How to find a square root on a calculator (step-by-step)

Method 1: Scientific calculator with a √ button

• Turn on the calculator.
• Type the number first (for example: 81).
• Press the √ key.
• Press = if your model requires it.

Result: you should see 9.

Method 2: Calculators where √ is a second function

Some calculators place square root above another key. In that case:

• Press 2nd, Shift, or Inv.
• Press the key that has √ printed above it.
• Enter your value and complete the expression if needed.

Method 3: Phone calculator (iPhone/Android)

• Open the calculator app.
• Rotate the phone to landscape (scientific mode).
• Tap √.
• Enter your number, or enter the number first depending on app behavior.

What if your calculator has no square root key?

You can still calculate square roots using exponents:

Square root of x = x^0.5

Example for √49:

• Enter 49
• Press exponent key: ^ or y^x
• Enter 0.5
• Press =

You will get 7.

Examples you can try now

Perfect squares

• √16 = 4
• √100 = 10
• √225 = 15

Non-perfect squares

• √5 ≈ 2.2361
• √50 ≈ 7.0711
• √200 ≈ 14.1421

Common mistakes and how to avoid them

• Typing order mistakes: some calculators need number first, others open a √( ) template first.
• Forgetting scientific mode: phone apps hide √ until landscape orientation.
• Confusing x² and √x: x² squares a number; √x does the inverse operation.
• Negative numbers: basic calculators cannot show imaginary results cleanly.

Can you find square roots of negative numbers?

In real-number math, square roots of negative numbers are not real. In advanced math, they are imaginary numbers:

√(-9) = 3i

Many classroom calculators show an error for negative square roots unless they support complex mode. The calculator at the top of this page returns the imaginary form when possible.

Quick mental check for your answer

After calculating, square your result to verify:

• If calculator says √72 ≈ 8.4853, check 8.4853 × 8.4853 ≈ 72
• This helps catch accidental key errors quickly

Final takeaway

If you remember one thing about how to find a square root on a calculator, remember this: look for √, enter your number carefully, and verify by squaring the result. Once you do it a few times, it becomes automatic.

Use the calculator above whenever you need fast, accurate square roots for homework, engineering, finance, coding, or everyday problem solving.