Geometry Calculator
Calculate 2D plane and 3D solid geometry shapes with instant formulas and metric outputs.
Geometry Formulas & How to Calculate
View All Math Formulas Handbook →Circle
$$ A = \pi r^2, \quad C = 2\pi r $$
Square radius and multiply by $\pi$ for area.
Triangle
$$ A = \frac{1}{2} b h, \quad P = a + b + c $$
Multiply base by vertical height and divide by 2.
Rectangle
$$ A = l \times w, \quad d = \sqrt{l^2 + w^2} $$
Diagonal calculated using Pythagorean theorem.
Cylinder
$$ V = \pi r^2 h, \quad A = 2\pi r(r + h) $$
Circular base area $\pi r^2$ multiplied by height $h$.
Sphere
$$ V = \frac{4}{3} \pi r^3, \quad A = 4 \pi r^2 $$
Cube the radius and multiply by $\frac{4}{3}\pi$.
Cone
$$ V = \frac{1}{3} \pi r^2 h, \quad l = \sqrt{r^2 + h^2} $$
One-third cylinder volume; slant height $l = \sqrt{r^2+h^2}$.