Equilateral Triangle Area Calculator
Work out the area, perimeter and height of an equilateral triangle from its side length free in your browser with this simple area calculator.
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Shape
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How to use this calculator
- Enter the side length.
- Press Calculate.
How it works
Area = (√3 ÷ 4) × side².
Worked example
2 m side. ≈ 1.73 m².
Common mistakes
- Using base × height ÷ 2 with the side as height — the height is √3/2 of the side, not the side itself.
- Applying the equal-sides formula to a triangle that isn't equilateral.
Frequently asked questions
How do I find an equilateral triangle's area?
Area = (√3 ÷ 4) × side², roughly 0.433 × side², since all three sides are equal.
What is its height?
The height is (√3 ÷ 2) × side, about 0.866 of the side length, dropping from a vertex to the opposite side.
What makes a triangle equilateral?
All three sides are equal and every angle is 60°. This shortcut formula only applies to that case.
Related tools
- Triangle Area Calculator
- Regular Pentagon Area Calculator
- Regular Polygon Area Calculator
- Square Area Calculator
- Ellipse Area Calculator
- Parallelogram Area Calculator
Explore more in Geometry, Shape, Area & Volume.
Cite this tool
Zerdly. (2026). Equilateral Triangle Area Calculator. Retrieved from https://www.zerdly.com/tools/equilateral-triangle-area-calculator/
Tip: Enter any known values to calculate the remaining results.
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