Geometry Lab formula guide

Volume & surface area formulas

Volume is the space inside a solid, in cubic units; surface area is the total area of its outer surface, in square units. For a cylinder, V = πr²h and S = 2πr² + 2πrh. For a sphere, V = ⁴⁄₃πr³ and S = 4πr².

Cylinder: V = πr²h · S = 2πr(r + h)

What each letter means

r, h
Radius and perpendicular height
w, h, d
Width, height, and depth (or l × w × h)
ℓ
Slant height of a cone or pyramid face
V, S
Volume (cubic units) and surface area (square units)
Try it with your own numbers

Volume & surface area formulas calculator

What fits inside, and what covers the outside. Change a value and the diagram, result, and working update together.

RectangleChange a dimension to explore
A = w × hDimensions shown in the selected unit

Give your shape a size.

Use the same unit for every dimension. Changing the unit relabels the measurements; it does not convert them.

From dimensions to an answer

The idea

Volume measures three-dimensional space in cubic units. Surface area measures the total outside covering in square units. A rectangular prism has volume whd and surface area 2(wh + wd + hd). A sphere has volume 4πr³/3 and surface area 4πr².

Volume and surface area formulas chart

SolidVolumeTotal surface area
Cube (edge s)V = s³S = 6s²
Rectangular prismV = whdS = 2(wh + wd + hd)
CylinderV = πr²hS = 2πr² + 2πrh
ConeV = ⅓πr²hS = πr² + πrℓ, ℓ = √(r² + h²)
SphereV = ⁴⁄₃πr³S = 4πr²
HemisphereV = ⅔πr³S = 3πr² (with base)
Square pyramid (base b)V = ⅓b²hS = b² + 2bℓ
Any prismV = base area × lengthS = 2 × base area + base perimeter × length

Worked examples

1Cube

  1. Edge 3 cm: V = 3³ = 27 cm³ and S = 6 × 3² = 54 cm².
  2. Double the edge to 6 cm: V = 216 cm³ (8 times larger) and S = 216 cm² (4 times larger).

Answer: Volume grows with the cube of the scale factor; surface area with its square.

2Cylinder

  1. r = 3 cm and h = 10 cm.
  2. V = π × 3² × 10 = 90π ≈ 282.74 cm³.
  3. S = 2π × 3² + 2π × 3 × 10 = 18π + 60π = 78π ≈ 245.04 cm².

Answer: About 282.74 cm³ and 245.04 cm².

3Cone

  1. r = 3 and vertical height h = 4, so ℓ = √(3² + 4²) = 5.
  2. V = ⅓ × π × 9 × 4 = 12π ≈ 37.70.
  3. S = π × 3 × (3 + 5) = 24π ≈ 75.40.

Answer: About 37.70 cubic units and 75.40 square units.

4Sphere

  1. r = 6 cm.
  2. V = ⁴⁄₃ × π × 6³ = 288π ≈ 904.78 cm³.
  3. S = 4π × 6² = 144π ≈ 452.39 cm².

Answer: About 904.78 cm³ (just over 0.9 liters) and 452.39 cm².

Common mistakes

  • Mixing up square and cubic units.
  • Using slant height for volume, or vertical height for a cone’s curved surface.
  • Forgetting a base, or including a missing top, in surface area.
  • Converting capacity incorrectly: 1 cm³ = 1 mL and 1,000 cm³ = 1 L.

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Volume & surface area formulas: common questions

Wondering about the why? Start here.

What is the difference between volume and surface area?

Volume measures how much space is inside a solid, in cubic units such as cm³. Surface area measures how much material covers the outside, in square units such as cm². Filling a box is about volume; wrapping it is about surface area.

Open the volume calculator
Can you convert volume to surface area?

Not directly. Different shapes with the same volume can have different surface areas. You need the dimensions: for a cube, find the edge s = ∛V, then S = 6s². A 64 cm³ cube has edge 4 cm and surface area 96 cm².

How do cubic centimeters relate to liters?

One cubic centimeter holds one milliliter, so 1,000 cm³ = 1 liter. One cubic meter holds 1,000 liters.