CALCULATOR
Regular Octagon Area Calculator
octagon. Example: Side: 2 m gives 19.313708499 m². Regular octagon only: 8 equal sides and equal interior angles. Computes area, not arbitrary polygon reconstruction. Flat Euclidean geometry in the stated units. No waste, thickness, structural advice or curved-earth inference. Only the stated forward job is supported; display rounding does not change the calculation.
Regular octagon only: 8 equal sides and equal interior angles. Computes area, not arbitrary polygon reconstruction. Flat Euclidean geometry in the stated units. No waste, thickness, structural advice or curved-earth inference. Only the stated forward job is supported; display rounding does not change the calculation. Derivation: Split into equal isosceles triangles; apothem is side/(2tan(π/n)).
Accepted inputs: Side: 0.001 to 1,000 m.
How the calculation works
A = 8s²/(4 tan(π/8))
Worked example
With side 2 m, octagon is 19.3137085 m².
Assumptions and limits
Regular octagon only: 8 equal sides and equal interior angles. Computes area, not arbitrary polygon reconstruction. Flat Euclidean geometry in the stated units. No waste, thickness, structural advice or curved-earth inference. Only the stated forward job is supported; display rounding does not change the calculation. Derivation: Split into equal isosceles triangles; apothem is side/(2tan(π/n)).