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Volume Calculator

Volume and surface area of a box, cube, cylinder, sphere, cone or pyramid in any unit — cubic meters, liters, gallons, cubic feet — with the formula shown.

Volume Calculator: with the default inputs, volume is 3 m³.

Try an example
Volume
3 m³
Surface area
13 m²
Assumptions
  • Worked steps are shown in meters (the internal base unit); the result is converted to the unit you choose. Internally volume is carried in liters (1 m³ = 1,000 L).
  • Pyramid means a right pyramid (apex above the centre of the rectangular base).
Volume formulas at a glance
ShapeVolumeSurface area
Boxlength × width × height2(lw + lh + wh)
Cubeside³6 × side²
Cylinderπ × r² × h2πr² + 2πrh
Sphere4⁄3 × π × r³4πr²
Coneπ × r² × h ÷ 3πr² + πr × √(r² + h²)
Pyramidbase area × h ÷ 3base + 4 triangular faces

Every cone or pyramid is exactly a third of the box or cylinder that contains it.

Math verified by automated testsUpdated 2026-09-082 sources cited

How this is worked out

The formula

Box  V = l·w·h,  S = 2(lw + lh + wh)
Cube  V = s³,  S = 6s²
Cylinder  V = π r² h,  S = 2πr² + 2πrh
Sphere  V = 4⁄3 π r³,  S = 4πr²
Cone  V = ⅓ π r² h,  S = πr² + πr·√(r² + h²)
Rectangular pyramid  V = ⅓ l·w·h,  S = lw + l·√((w/2)² + h²) + w·√((l/2)² + h²)
1 m³ = 1,000 L = 264.17 US gal = 35.31 ft³

Open How it’s calculated above to see this worked through with your own numbers.

What you enter

Shape
Only the dimensions for the selected shape are used; the rest are ignored.Box (rectangular prism) · Cube · Cylinder · Sphere · Cone · Pyramid (rectangular base)
Length
A number.in mm, cm, m, in, ft, yd · 0 or more · defaults to 2
Width
A number.in mm, cm, m, in, ft, yd · 0 or more · defaults to 1.5
Height
A number.in mm, cm, m, in, ft, yd · 0 or more · defaults to 1
Side
A number.in mm, cm, m, in, ft, yd · 0 or more · defaults to 1
Radius
A number.in mm, cm, m, in, ft, yd · 0 or more · defaults to 0.5
Height
A number.in mm, cm, m, in, ft, yd · 0 or more · defaults to 2
Radius
A number.in mm, cm, m, in, ft, yd · 0 or more · defaults to 1
Base radius
A number.in mm, cm, m, in, ft, yd · 0 or more · defaults to 1
Height
Perpendicular height from base to apex, not the slant.in mm, cm, m, in, ft, yd · 0 or more · defaults to 3
Base length
A number.in mm, cm, m, in, ft, yd · 0 or more · defaults to 2
Base width
A number.in mm, cm, m, in, ft, yd · 0 or more · defaults to 2
Height
Perpendicular height from base to apex.in mm, cm, m, in, ft, yd · 0 or more · defaults to 3

What you get back

Volumemain answer
Surface area

What this assumes

  • Worked steps are shown in meters (the internal base unit); the result is converted to the unit you choose. Internally volume is carried in liters (1 m³ = 1,000 L).
  • Pyramid means a right pyramid (apex above the centre of the rectangular base).

About this calculator

Volume is the amount of space a solid takes up, measured in cubic units — or, for anything that holds liquid, in liters and gallons. This calculator gives the volume and the surface area of the six solids that cover almost every practical problem, from shipping boxes to water tanks to grain silos.

How to use it

Choose the shape and enter its dimensions in any length unit. The volume can be shown in cubic meters, liters, cubic feet, gallons and more, so "how many gallons does this cylindrical tank hold?" is a single calculation. Surface area is useful for paint, wrapping, sheet metal and heat loss.

Three ideas behind all the formulas

  1. Prisms and cylinders: base × height. A box is a stack of identical rectangles; a cylinder is a stack of identical circles. Volume = area of the base × how tall the stack is.
  2. Pointed solids are one third of the matching prism. A cone holds exactly a third of the cylinder with the same base and height; a pyramid holds a third of its box. You can verify it by pouring — three cones of water fill the cylinder.
  3. Spheres: 4⁄3 πr³. Archimedes showed a sphere is two-thirds of the cylinder that just contains it (radius r, height 2r), and he was proud enough to have it carved on his tomb.

Surface area

Surface area is the total area of the outside skin: unfold the solid into flat pieces and add them up. A cylinder unfolds into two circles and a rectangle whose width is the circumference; a cone into a circle and a sector whose slant edge is √(r² + h²).

Units

Cubic units scale by the cube of the length factor: 1 m³ = 1,000,000 cm³ = 1,000 L, and 1 yd³ = 27 ft³, not 3. That's why a "small" change in dimensions makes a big change in capacity — doubling a tank's radius quadruples its volume; doubling every dimension of a box makes it hold eight times as much.

Common mistakes

  • Using diameter where the formula wants radius (this over-counts by 4×).
  • Using the slant height of a cone or pyramid as its height. The volume formula wants the perpendicular height; the slant appears only in surface area.
  • Converting cubic units by the linear factor.

Frequently asked questions

How do I find the volume of a cylinder?

Multiply the base area by the height: V = πr²h. A tank with radius 2 ft and height 5 ft holds π × 4 × 5 ≈ 62.8 ft³, about 470 US gallons.

How many liters are in a cubic meter?

Exactly 1,000. A liter is a cube 10 cm on a side, and 10 × 10 × 10 of them fill a cubic meter.

Why is a cone's volume one third of a cylinder's?

Because its cross-sections shrink to a point. Calculus makes it exact (integrating πr²(1 − z/h)² from 0 to h gives ⅓πr²h), but you can check it by filling a cone with water three times into a cylinder of the same base and height.

What's the difference between volume and surface area?

Volume is the space inside (cubic units, or liters/gallons); surface area is the total area of the outside faces (square units). A 1 m cube has volume 1 m³ and surface area 6 m².

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