# Equilateral Triangle Area Calculator

Created by Steven Wooding
Reviewed by Krishna Nelaturu
Last updated: May 24, 2022

With this equilateral triangle area calculator, you are able to compute the area of an equilateral triangle simply by entering either its side length or its height. Perfect if you want to know the area of your tortilla chip snack 😋 or a road sign 🚸

• What is an equilateral triangle, and how is it defined?
• How to calculate the area of an equilateral triangle from its formula.
• How to find the area of an equilateral triangle with its height.

## What is an equilateral triangle?

An equilateral triangle is a particular triangle where all three sides are the same length. Given this restriction, it also means that all three angles of an equilateral triangle are the same – 60°.

Equilateral triangles are a special case of isosceles triangles, with all three sides equal.

## How to calculate the area of an equilateral triangle

There are two main ways to calculate the area of an equilateral triangle. Either by using the length of its side or the equilateral triangle's height. The formula for area $A$ using the equilateral triangle's side is:

$A = \frac{\sqrt{3}}{4}a^2$

...where $a$ is the side length of the equilateral triangle.

If the height of the equilateral triangle is what you know, we can use it alone to calculate the area. Given the relationship between side length and height $h$:

$h = \frac{\sqrt{3}}{2}a$

...we can rearrange this and substitute for $a$ in the area equation to get:

$A = \frac{4\sqrt{3}}{12}h^2$

## How to use this equilateral triangle area calculator

It really couldn't be simpler. Just enter the length of the side of the equilateral triangle, and you will be instantly shown its area. No wasted time clicking a calculate button.

Alternatively, enter the height to get the area of your equilateral triangle. As a bonus, it also gives you the side length as well.

Depending on the size of your equilateral triangle, you can change the units of the lengths and area to best match your application.

If you want a more general equilateral triangle calculator, then the equilateral triangle calculator is what you need. It also calculates an equilateral triangle's perimeter, circumcircle radius, and incircle radius. Or even more general is the triangle area calculator.

## FAQ

### How many degrees in each angle of an equilateral triangle?

60°. Recall from elementary geometry that the inside angles of any triangle add up to 180°. Since for an equilateral triangle, the inside angles are all the same, one inside angle is 180° divided by 3, which equals 60°.

### What's the area of an equilateral triangle with a side length of 5 inches?

10.83 square inches. To get this answer, you perform the following steps:

1. Square the side length of the equilateral triangle.
2. Multiply the result by the square root of three.
3. Divide by four.

Mathematically, that is:

Area = √3 × a² / 4 = 1.734 × 25 / 4 = 10.83 in²

Steven Wooding Side (a)
in
Height (h)
in
Area (A)
in²
People also viewed…

### Car heat

The hot car calculator shows you how fast the interior of a car heats up during a summers day.

### Circle measurements

Our circle measurements calculator helps to calculate the radius, diameter, circumference and area of a circle.

### Graphing inequalities on a number line

The graphing inequalities on a number line calculator allows up to three inequalities on one picture, and even returns what numbers satisfy all of them.

### Helium balloons

Wondering how many helium balloons it would take to lift you up in the air? Try this helium balloons calculator! 🎈 