Volume measures the amount of three-dimensional space a solid object occupies, expressed in cubic units (cm³, m³, in³, ft³). The volume formula depends on the shape: rectangular prism: V = l × w × h; cylinder: V = πr²h; cone: V = ⅓πr²h; sphere: V = 4/3πr³. Volume is tested on the SAT Math section and covered in Florida MAFS geometry standards (grades 7–11).

"Volume" Explained

Volume Formula: Master 5 Shapes with SAT Examples

Volume measures how much three-dimensional space a solid occupies, expressed in cubic units (cm³, m³, in³). The formula depends on the shape — prism, cube, cylinder, cone, or sphere — and it’s tested across the SAT Math section and Florida MAFS geometry standards.

Volume

DEFINATION

What Volume Means

Volume is how much three-dimensional space an object takes up. Unlike area, which measures a flat surface in square units, volume measures the interior of a solid in cubic units. Florida MAFS standards (MAFS.7.G.B.6, MAFS.912.G-GMD.1) expect students to find the volume of prisms, cylinders, pyramids, cones, and spheres, the same shapes the SAT tests.

THE 5 FORMULAS

Volume Formulas for Every Shape

The formula you use depends on the shape. These five cover every volume question on Florida MAFS and the SAT,  learn all five.

Rectangular Prism
V = l × w × h
l = length · w = width · h = height · cubic units
Most common prism on FSA assessments (MAFS.7.G.B.6).
Cube
V = s³
s = side length (all sides equal). Shortcut from V = lwh when l = w = h.
SAT favorite for "find the side given the volume" problems.
Cylinder
V = πr²h
r = radius of circular base · h = height · π ≈ 3.14159 (MAFS.912.G-GMD.1)
Cone
V = ⅓πr²h
r = base radius · h = height · exactly ⅓ the cylinder with the same base and height.
SAT rule: if a cone fits inside a cylinder, V_cone = ⅓ V_cylinder.
Sphere
V = 4/3 πr³
r = radius
Most commonly misremembered — note the 4/3 coefficient.

THE STRATEGY

Volume on the SAT Math Section

SAT volume problems rarely ask you to just plug in numbers, expect to find a missing dimension, compare two volumes, or work out how many smaller containers fit inside a larger one.

SAT reference-sheet reminder: the SAT provides V = πr²h (cylinder), V = ⅓πr²h (cone), and V = 4/3πr³ (sphere). It does NOT provide V = lwh (prism) or V = s³ (cube) — know those cold before test day.

STEP BY STEP

Worked Examples

Rectangular prism — a fish tank 40 cm long, 20 cm wide, 25 cm tall. Find the volume.

  • 1. Formula: V = l × w × h
  • 2. Substitute: 40 × 20 × 25
  • 3. Multiply: 20,000

V = 20,000 cm³

Cylinder — radius 5 cm, height 12 cm. Find the volume (π = 3.14).

  • 1. Formula: V = πr²h
  • 2. Square the radius: r² = 5² = 25
  • 3. Substitute: 3.14 × 25 × 12
  • 4. Multiply: 942

V ≈ 942 cm³

Cone vs. cylinder — same base (r = 6 in) and height (10 in). The full cylinder of water is poured into the cone until full. How much water remains in the cylinder?

  • 1. Cylinder: V = π(6²)(10) = 360π in³
  • 2. Cone: V = ⅓π(6²)(10) = 120π in³
  • 3. Remaining: 360π − 120π = 240π

240π ≈ 753.98 in³ remains in the cylinder

WHY "CUBIC"

Volume Units

Every volume answer is in cubic units because volume measures three dimensions at once. Leaving an answer in square units (cm²) is a common Florida MAFS and SAT error.

Measurement System Common Volume Units Conversion
Metric cm³, m³, mm³, L, mL 1 L = 1,000 cm³
US Customary in³, ft³, yd³ 1 ft³ = 1,728 in³
Fluid (liquid) fl oz, cups, gallons 1 gallon = 231 in³

AVOID THESE

Common Volume Mistakes — and How to Fix Them

The Mistake ✕ Wrong ✓ Correct
Using diameter instead of radius in πr²h or ⁴/₃πr³ V = π(10)²(5) when r = 5 was given V = π(5)²(5) = 125π — halve the diameter before squaring
Forgetting the ⅓ in the cone formula V = πr²h (cylinder formula on a cone) V = ⅓πr²h — a cone holds one-third of the cylinder
Answering in square units instead of cubic V = 200 cm² (area units) V = 200 cm³ — volume always uses cubic units

TRY THESE

Practice Problems

Work each one, then reveal the answer to check yourself.

Easy

A cube has a side length of 7 cm. What is its volume?

V = s³ = 7³ = 343 cm³
Medium

A sphere has a radius of 3 in. Find its volume in terms of π.

V = ⁴/₃πr³ = ⁴/₃π·27 = 36π in³
SAT-Level

A cylindrical tank has a diameter of 8 ft and height 15 ft. How many cubic feet of water (nearest whole)?

r = 4 ft · V = π(4²)(15) = 240π ≈ 754 ft³

Volume Formula — FAQ

What is the volume formula and how do I use it?

It depends on the shape: prism V = lwh, cylinder V = πr²h, cone V = ⅓πr²h, sphere V = ⁴/₃πr³. Identify the shape, substitute the dimensions, and solve — always in cubic units. Florida MAFS covers all five from grade 7 through 11.

Is the volume formula on the SAT?

Yes — cylinders, cones, and spheres, with formulas on the reference sheet. It does not provide V = lwh or V = s³, so memorize those. SAT volume problems are usually multi-step: a missing dimension, comparing volumes, or combining shapes.

What's the difference between volume and surface area?

Volume measures the space inside (cubic units, cm³); surface area measures the outer surface (square units, cm²). Fill a box with water → volume. Wrap it in paper → surface area. The units tell you which you're calculating.

Why does the cone volume formula have a ⅓?

Because exactly three identical cones (same base and height) fill one cylinder — Cavalieri's Principle (MAFS.912.G-GMD.1). Vcone = ⅓ Vcylinder is the single most important cone fact, and the SAT tests it directly in "fill the cone from the cylinder" problems.

How do I study volume formulas for the EOC or SAT?

Three steps: (1) write all five formulas from scratch daily for a week; (2) do one worked example per shape until substitution is automatic; (3) practice SAT multi-step problems where you choose the formula first. InLighten's program in Orlando, Winter Park, and Lake Nona structures practice exactly this way.

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