Cube Root of 3 — Value, Steps, and Estimation

#Algebra
TL;DR
The cube root of 3 is $\sqrt[3]{3} \approx 1.442$, an irrational number that cannot be simplified because 3 is prime. This article shows why the radical stays as is, how to estimate its value by hand, where it appears, common mistakes, and worked examples.
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Bhanzu TeamLast updated on July 19, 20264 min read

The cube root of 3 is $\sqrt[3]{3} \approx 1.442$, and unlike many radicals, it does not simplify at all.

Quick Answer:

Result: $\sqrt[3]{3} \approx 1.442$

Notation: $\sqrt[3]{3}$ or $3^{1/3}$

Method shown: estimation between neighbouring cubes

Approximate value: $1.442$ (to 3 decimal places, irrational)

Exact form: $\sqrt[3]{3}$ (already in simplest radical form)

Quick Reference Table

Number

Simplified cube root

Decimal (3 dp)

$\sqrt[3]{1}$

$1$

$1.000$

$\sqrt[3]{2}$

$\sqrt[3]{2}$

$1.260$

$\sqrt[3]{3}$

$\sqrt[3]{3}$

$1.442$

$\sqrt[3]{4}$

$\sqrt[3]{4}$

$1.587$

$\sqrt[3]{5}$

$\sqrt[3]{5}$

$1.710$

$\sqrt[3]{8}$

$2$

$2.000$

Where the Cube Root of 3 Appears

The cube root of 3 is the edge length of a cube whose volume is 3 cubic units. It also turns up in engineering scaling laws: to triple the volume of a cube-shaped object while keeping its proportions, every edge must grow by a factor of $\sqrt[3]{3} \approx 1.442$, not by 3.

What Is the Cube Root of 3?

The cube root of a number is the value that, multiplied by itself three times, gives that number. Since no whole number cubed equals 3, the cube root of 3 sits between $1^3 = 1$ and $2^3 = 8$.

The result is an irrational number that never terminates and never repeats. Because 3 is prime, it has no perfect-cube factor to pull out, so $\sqrt[3]{3}$ is already in its simplest form, a point that connects directly to the ideas in cube numbers and radicals.

How to Find the Cube Root of 3 (Methods)

Method 1: Estimation between neighbouring cubes

Locate 3 between the two nearest perfect cubes.

$$1^3 = 1$$ $$2^3 = 8$$

So $\sqrt[3]{3}$ lies between 1 and 2, and much closer to 1 because 3 is close to 1. Testing $1.4$:

$$1.4^3 = 2.744$$

That is below 3, so try $1.45$:

$$1.45^3 \approx 3.048$$

That is just above 3, so the answer sits between 1.44 and 1.45. Testing $1.442$:

$$1.442^3 \approx 2.999$$

Final answer: $\sqrt[3]{3} \approx 1.442$ to three decimal places.

Method 2: Why it will not simplify

Write 3 in terms of its prime factors.

$$3 = 3$$

For a factor to leave a cube root, it must appear three times. The single 3 has no group of three.

$$\sqrt[3]{3} = \sqrt[3]{3}$$

Final answer: $\sqrt[3]{3}$ is already in simplest radical form.

Common Mistakes With Cube Root of 3

Mistake 1: Dropping the cube-root index

Where it slips in: writing the radical quickly.

Don't do this: writing $\sqrt{3}$ when you mean the cube root.

The correct way: always show the index: $\sqrt[3]{3}$. Without the little 3 it reads as a square root, giving $\approx 1.732$ instead of $\approx 1.442$.

Mistake 2: Trying to simplify a prime radical

Where it slips in: assuming every cube root breaks down like $\sqrt[3]{24} = 2\sqrt[3]{3}$.

Don't do this: writing $\sqrt[3]{3}$ as some product of smaller radicals.

The correct way: a prime number under a cube root has no perfect-cube factor, so it stays as $\sqrt[3]{3}$.

Mistake 3: Confusing $\sqrt[3]{3}$ with $\dfrac{3}{3}$ or $3 \div 3$

Where it slips in: reading the radical as ordinary division.

Don't do this: answering 1.

The correct way: the cube root asks "what number cubed gives 3?" The answer is $\approx 1.442$, not 1.

To build cube-root fluency with a teacher, explore Bhanzu's algebra tutor or math classes online.

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Frequently Asked Questions

What is the cube root of 3?
The cube root of 3 is $\sqrt[3]{3} \approx 1.442$, an irrational number.
Can the cube root of 3 be simplified?
No. Because 3 is prime, it has no perfect-cube factor, so $\sqrt[3]{3}$ is already in simplest radical form.
Is the cube root of 3 rational or irrational?
Irrational. Since 3 is not a perfect cube, $\sqrt[3]{3}$ is a non-terminating, non-repeating decimal.
What is the cube root of 3 in exponential form?
It is $3^{1/3}$, which is the same as $\sqrt[3]{3}$.
How is $\sqrt[3]{3}$ different from $\sqrt{3}$?
$\sqrt{3} \approx 1.732$ asks which number squared gives 3, while $\sqrt[3]{3} \approx 1.442$ asks which number cubed gives 3. The index changes the answer.
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