A rectangular prism volume calculator determines the enclosed space of any six-faced rectangular solid. Enter length, width, and height for instant results in any volume unit.
A rectangular prism is a 3D polyhedron with 6 rectangular faces, 12 edges, and 8 vertices. It is also called a cuboid. All internal angles are right angles (90°). The three pairs of opposite faces are congruent rectangles.
A rectangular prism is the mathematical term for what most people call a "box." It is the most common 3D shape in architecture, packaging, and manufacturing.
Volume = length × width × height (V = l × w × h).
The formula multiplies the area of the base (l × w) by the height (h). All dimensions must be in the same unit before multiplication.
Example: A prism 8 m × 5 m × 3 m: V = 8 × 5 × 3 = 120 m³ = 120,000 L = 31,700 US gal = 4,238 ft³.
10 m × 8 m × 0.15 m = 12 m³ of concrete needed.
2.4 m × 1.2 m × 0.3 m = 0.864 m³ = 864 L of soil.
Interior 4.1 × 2.1 × 2.1 m = 18.08 m³ = 639 ft³ capacity.
12 × 6 × 1.5 m average depth = 108 m³ = 108,000 L = 28,531 gal.
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Answers to common questions about the rectangular prism volume calculator.
Yes. "Rectangular prism" and "cuboid" are two names for the same shape — a 3D solid with 6 rectangular faces. "Box" is the informal name.
SA = 2(lw + wh + lh). For a 4 × 3 × 2 prism: SA = 2(12 + 6 + 8) = 52 square units.
d = √(l² + w² + h²). For a 3 × 4 × 5 prism: d = √(9 + 16 + 25) = √50 ≈ 7.07 units.
Yes. If two dimensions are equal (e.g., l = w), two faces will be squares. If all three are equal (l = w = h), every face is a square and the shape becomes a cube.
Calculate V = l × w × h in cm, divide by 1,000 for liters: a 60 × 30 × 40 cm tank = 72,000 cm³ = 72 liters = 19 US gallons.