Current for 2026•As of: July 2026

Area & Volume Calculator calculate area and volume.

Calculate area and volume – rectangle, circle, triangle, cuboid, cylinder and sphere

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Area & Volume Calculator

Calculate the area and volume of geometric shapes – rectangle, circle, triangle, cuboid, cylinder and sphere.

Enter dimensions

0.1 50
0.1 50

Area

20

Area units²

Formula

A = a × b = 4 × 5 = 20

Calculate area: formulas for every shape

Circle area, rectangle and triangle – the most important area formulas

Calculating the area is one of the most common tasks in mathematics, trades and everyday life. The basic formula varies depending on the geometric shape: for a rectangle, the formula is A = a × b (length times width). When calculating a circle, the formula is A = π × r² – the so-called circle area formula, which squares the radius r and multiplies it by the constant π (≈ 3.14159). For a triangle, the formula is A = (g × h) / 2, i.e. base times height, halved.

The circle area is especially important in engineering and technology – for example when calculating pipe diameters, discs or round base areas. The radius is always half the distance from the center to the edge. If you only know the diameter d, then r = d ÷ 2. Our calculator shows the complete formula with the values inserted for every calculation, so you can follow the calculation step by step.

Calculate volume: cuboid, cylinder and sphere

Formulas and examples for the most important solids

Calculating the volume of geometric solids follows its own formula for each shape. A cuboid has the volume V = a × b × c (length × width × height). When calculating cylinder volume, the formula is V = π × r² × h – the circular base area multiplied by the height. The volume of a sphere is given by V = (4/3) × π × r³.

All three volume formulas build on area calculation: a cuboid's base is a rectangle (a × b), a cylinder's base is a circle (π × r²). For a cube, a = b = c, so V = a³. Cylinder volume is especially relevant in practice – for example for tanks, pipes and cans. Sphere volume is frequently needed in physics and chemistry, e.g. for molecule diameters or storage tanks.

Calculate circle area – circle with radius 5 cm

Calculate circle area – circle with radius 5 cm
ItemAmount
FormulaA = π × r²
Radius r5 cm
r²25 cm²
π × 25≈ 78.54 cm²
Circle area≈ 78.54 cm²

Calculate cylinder volume – r = 3 cm, h = 10 cm

Calculate cylinder volume – r = 3 cm, h = 10 cm
ItemAmount
FormulaV = π × r² × h
Radius r3 cm
Height h10 cm
Base area π × 3²≈ 28.274 cm²
Volume 28.274 × 10≈ 282.74 cm³

Calculate rectangle area – a = 6 m, b = 4 m

Calculate rectangle area – a = 6 m, b = 4 m
ItemAmount
FormulaA = a × b
Side a6 m
Side b4 m
Area24 m²

Frequently asked questions about the Area & Volume Calculator

Formulas, examples and tips for geometry calculations

You calculate the area of a circle with the formula A = π × r², where r is the radius of the circle. For example, if a circle has a radius of 5 cm, the result is A = π × 5² ≈ 78.54 cm². If you know the diameter (d), then r = d ÷ 2. Our calculator performs the calculation instantly as soon as you enter the radius.

You calculate cylinder volume with V = π × r² × h, where r is the radius of the base and h is the height of the cylinder. Example: radius 3 cm, height 10 cm → V = π × 9 × 10 ≈ 282.74 cm³. The base is a circle (π × r²), which multiplied by the height gives the volume.

You calculate the area of a rectangle with A = a × b, i.e. length times width. Example: a = 6 m, b = 4 m → A = 24 m². For a square, a = b, so A = a². The area of a rectangle is the simplest area calculation and forms the basis for many other geometric formulas.

You calculate the volume of a sphere with V = (4/3) × π × r³, where r is the radius of the sphere. Example: r = 4 cm → V = (4/3) × π × 64 ≈ 268.08 cm³. The formula shows that volume grows cubically with the radius – a sphere with twice the radius has eight times the volume.

You calculate the area of a triangle with A = (g × h) / 2, i.e. base times height divided by 2. Example: g = 8 cm, h = 5 cm → A = (8 × 5) / 2 = 20 cm². The height must be perpendicular to the base. This relationship holds for every triangle – whether right-angled, isosceles or scalene.

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