Regular Pentagon Area Calculator
Calculate the area, perimeter and apothem of a regular pentagon from its side length free in your browser with this simple pentagon area calculator.
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Shape
Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.
How to use this calculator
- Enter the side length.
- Press Calculate.
How it works
Area = ¼ × √(5(5 + 2√5)) × side² ≈ 1.720 × side².
Worked example
2 m side. ≈ 6.88 m².
Common mistakes
- Using the side as the apothem — the apothem is shorter than the side.
- Applying it to irregular pentagons; this formula needs equal sides.
Frequently asked questions
How do I find a regular pentagon's area?
Area ≈ 1.720 × side² (exactly ¼ × √(5(5 + 2√5)) × side²) for a five-sided shape with equal sides and angles.
Can I use it for any pentagon?
Only regular ones. For an irregular pentagon, split it into triangles and add their areas instead.
Does this work for any pentagon?
Only a regular pentagon (equal sides and angles). For an irregular one, divide it into triangles and add their areas.
Related tools
- Regular Hexagon Area Calculator
- Regular Polygon Area Calculator
- Trapezoid Area Calculator
- Ellipse Area Calculator
- Equilateral Triangle Area Calculator
- Parallelogram Area Calculator
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Cite this tool
Zerdly. (2026). Regular Pentagon Area Calculator. Retrieved from https://www.zerdly.com/tools/regular-pentagon-area-calculator/
Tip: Enter any known values to calculate the remaining results.
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