Geometric Calculator
Area, perimeter, volume, surface area and diagonals for 2D and 3D shapes, with a live diagram.
Area
78,54
Circumference
31,416
Diameter
10
Area 78,54
📐 About This Calculator
Pick a 2D or 3D shape and enter its dimensions to get area, perimeter, volume, surface area and diagonals. The diagram updates live as you type.
Circle: Area = π·r² | Circumference = 2πr
Rectangle: Area = l·w | Diagonal = √(l²+w²)
Triangle (Heron): s=(a+b+c)/2, Area = √(s(s−a)(s−b)(s−c))
Sphere: Vol = 4/3·π·r³ | Surface = 4πr²
Cone: Vol = ⅓·π·r²·h | Slant = √(r²+h²)
Variable Definitions:
- • r = Radius
- • l, w, h = Length, width, height
- • s = Side / semi-perimeter (Heron)
✅ Best used for:
- • School and college geometry
- • Construction and design
- • Quick engineering estimates
⚠️ Limitations:
- • Irregular polygons: use the Land calculator
- • Assumes exact, regular shapes
📖 How Geometric Shapes are Calculated
Choosing a shape and units
Select a 2D or 3D shape; the inputs change to match. Enter all dimensions in the same unit.
Heron's formula and triangle angles
With three sides you can get the area (Heron) and all three angles (Law of Cosines) — no height needed.