Volume & 3D Geometry Calculators

Choose a solid to calculate volume, surface area and related dimensions, then inspect a proportionally drawn isometric figure. Below the tools, learn how cubic units, capacity, surface area and composite solids relate.

CubeVolume, surface area and diagonals from one side.Rectangular PrismLength × width × height, plus surface area.CylinderCircular prism: volume, surface and lateral area.PipeHollow cylinder — wall material, not the bore.CapsuleCylinder with hemispherical ends — tanks and pills.ConeVolume, slant height and surface area.SphereThe four-thirds rule, from one radius.Square PyramidSquare base to an apex; volume and faces.FrustumTruncated cone between two radii.Triangular PrismTriangle swept along a length.HemisphereHalf a sphere — dome plus flat base.Spherical CapDome sliced from a sphere, from base and rise.EllipsoidA sphere stretched along three axes.TorusRing or doughnut, from two radii.Polygon PrismRegular prism with any number of sides. Tank Fill LevelHorizontal tank part-full — depth to litres.

About these calculators

Each tool takes the measurements that define its solid and returns the volume, the surface area and the properties that matter for that shape — slant heights, diagonals, lateral areas and diameters. Every figure is an orthographic isometric projection drawn to the proportions you enter, with CAD-style dimension lines, so the picture always matches the numbers.

Volumes and surface areas use exact formulas, with one exception: the ellipsoid's surface area has no closed elementary form and uses a close approximation. Switch between millimetres, centimetres, metres, inches or feet at any time, and choose how many decimal places to show.

3D geometry guide

Volume measures enclosed three-dimensional space

Volume uses cubic units because three independent lengths are multiplied. Common units include mm³, cm³, m³, in³ and ft³. Capacity is often expressed in litres: 1 litre = 1,000 cm³ and 1 m³ = 1,000 litres.

Choose the quantity

Volume vs surface area

Volume answers how much space is enclosed or material is occupied. Surface area answers how much covers the outside or inside faces. Tank capacity uses volume; paint or lining uses surface area.

Compare the four measures →
Composite geometry

Combine simpler solids

A capsule tank combines a cylinder with two hemispherical ends. A hopper may combine a prism and a frustum. Calculate each part in consistent units, then add solid regions or subtract voids.

Try the capsule calculator →
Distinctive tool

Horizontal Tank Fill

Fluid volume is nonlinear with depth because the filled circular segment changes width. Model flat or hemispherical ends and see depth, volume and percentage together.

Open Tank Fill →

Choosing the right solid

Use a rectangular prism for box-like forms, a cylinder for a circular section carried along a length, a sphere or ellipsoid for rounded bodies, a cone or frustum for tapering forms, and a triangular or polygon prism for constant non-rectangular sections. A capsule represents a cylinder with hemispherical ends, while a torus models a ring.

Worked example: rectangular box volume

Inputs: length 2 m, width 1.5 m, height 0.8 m.

V = L × W × H = 2 × 1.5 × 0.8 = 2.4 m³

Result: 2.4 m³, equivalent to 2,400 litres of ideal internal capacity. Real capacity requires internal dimensions and allowances for wall thickness, fittings and unusable space.

For a fuller explanation of units, models and practical examples, read Area vs Perimeter vs Surface Area vs Volume.