Square Root Calculator

Calculate square roots, nth roots, simplify radicals, check perfect squares, and more. A complete toolkit for all your radical and root calculations.

Square Root Calculator

Nth Root Calculator

Calculate the nth root of a number
Result
-

Perfect Square Checker

Result
-

Square a Number

²
Result
-

Simplify Square Root

Enter a number to simplify its square root
Simplified Form
-

Square Root of Fraction

Result
-

Add/Subtract Roots

Result
-

Multiply/Divide Roots

Result
-

Estimate Square Root

See which perfect squares it falls between
Estimation
-

Perfect Squares Reference Table

n √n²
111
242
393
4164
5255
6366
7497
8648
9819
1010010
n √n²
1112111
1214412
1316913
1419614
1522515
1625616
1728917
1832418
1936119
2040020
n √n²
2144121
2248422
2352923
2457624
2562525
3090030
40160040
50250050
10010000100
100010000001000

Common Square Roots Values

√2
≈ 1.41421
√3
≈ 1.73205
√5
≈ 2.23607
√6
≈ 2.44949
√7
≈ 2.64575
√8
≈ 2.82843
√10
≈ 3.16228
√12
≈ 3.46410

Square Root Formulas & Properties

Basic Definition

√a = b means b² = a

The square root of a is b if b squared equals a.

Product Rule

√(a × b) = √a × √b

The root of a product equals the product of roots.

Quotient Rule

√(a / b) = √a / √b

The root of a quotient equals the quotient of roots.

Power Rule

√(a²) = |a|

The square root of a squared is the absolute value.

Exponent Form

√a = a^(1/2)

Square root can be written as a fractional exponent.

Nth Root

ⁿ√a = a^(1/n)

Any root can be expressed as a fractional power.

How to Simplify Square Roots

1

Find Perfect Square Factors

Find the largest perfect square that divides into your number.

Example: √72 → 72 = 36 × 2 (36 is a perfect square)
2

Apply Product Rule

Separate the perfect square from the other factor.

Example: √72 = √36 × √2
3

Simplify the Perfect Square

Take the square root of the perfect square factor.

Example: √36 × √2 = 6√2
4

Write Final Answer

Express in simplified radical form: coefficient × √remaining

Answer: √72 = 6√2 ≈ 8.485

Real-World Square Root Applications

Pythagorean Theorem

Find the hypotenuse: a² + b² = c²

Example: sides 3 and 4
c = √(3² + 4²) = √25 = 5

Area to Side Length

Find the side of a square given its area

Example: Area = 144 sq ft
Side = √144 = 12 ft

Distance Formula

Distance between two points

Formula: d = √[(x₂-x₁)² + (y₂-y₁)²]
Points (0,0) to (3,4): d = 5

Standard Deviation

Statistical measure of spread

Formula: σ = √(variance)
Used in statistics and data analysis

Screen Diagonal

Calculate TV/monitor diagonal size

Example: 48" × 27" screen
Diagonal = √(48² + 27²) ≈ 55"

Sound & Waves

RMS voltage calculations

Formula: V_rms = V_peak / √2
Used in audio and electrical engineering

Methods to Calculate Square Roots

Prime Factorization

  1. Factor the number into primes
  2. Pair up identical prime factors
  3. Take one from each pair outside the radical
√72 = √(2×2×2×3×3) = 2×3×√2 = 6√2

Estimation Method

  1. Find two perfect squares it's between
  2. Make an educated guess
  3. Refine by squaring your guess
√50: Between √49=7 and √64=8, so ≈ 7.07

Babylonian Method

  1. Start with a guess (x₀)
  2. Improve: x₁ = (x₀ + n/x₀) / 2
  3. Repeat until accurate enough
√10: x₀=3, x₁=(3+10/3)/2 ≈ 3.167

Frequently Asked Questions

What is a square root?

A square root of a number is a value that, when multiplied by itself, gives the original number. For example, √25 = 5 because 5 × 5 = 25. Every positive number has two square roots: one positive (principal) and one negative.

Can you take the square root of a negative number?

Not in the real number system. The square root of a negative number involves imaginary numbers. For example, √(-1) = i (the imaginary unit). √(-9) = 3i.

What is a perfect square?

A perfect square is an integer that is the square of another integer. Examples: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, etc. Their square roots are whole numbers.

How do I simplify a square root?

Factor the number inside the radical, find perfect square factors, take their root outside the radical. For example, √48 = √(16×3) = 4√3.

What is the difference between √ and ³√?

√ (square root) asks "what number squared equals this?" while ³√ (cube root) asks "what number cubed equals this?" √8 ≈ 2.83, but ³√8 = 2 (because 2³ = 8).

Is √2 a rational number?

No, √2 is irrational. It cannot be expressed as a simple fraction and its decimal expansion never ends or repeats. √2 ≈ 1.41421356... This was proven by ancient Greek mathematicians.