Geometry Formulas

Area, perimeter, surface area, and volume formulas for common 2D and 3D shapes.

Reference Reference Updated Apr 19, 2026
Reference

2D shapes

Shape Area Perimeter
Square (side s) 4s
Rectangle (w × h) w · h 2(w + h)
Triangle (b, h) ½ b · h a + b + c
Equilateral triangle (s) (√3 / 4) s² 3s
Circle (r) π r² 2π r
Ellipse (a, b) π a b ≈ π[3(a+b) − √((3a+b)(a+3b))]
Parallelogram (b, h) b · h 2(a + b)
Trapezoid (a, b, h) ½ (a + b) h a + b + c + d
Regular n-gon (n, s) (n s² / 4) cot(π/n) n · s
Circular sector (r, θ rad) ½ r² θ r(2 + θ)

3D shapes

Solid Volume Surface area
Cube (s) 6s²
Rectangular box (w, h, d) w h d 2(wh + hd + wd)
Sphere (r) (4/3) π r³ 4π r²
Cylinder (r, h) π r² h 2π r (r + h)
Cone (r, h) (1/3) π r² h π r (r + √(r² + h²))
Pyramid (base A, h) (1/3) A h A + ½ · perim · slant
Torus (R, r) 2π² R r² 4π² R r