A box volume calculator computes how much space a rectangular box (cuboid) can hold. Enter length, width, and height to get instant results in cubic centimeters, liters, gallons, cubic feet, or any of 30+ volume units.
A box (cuboid or rectangular prism) is a 3D shape with 6 rectangular faces. Opposite faces are identical. The box is defined by three dimensions: length (l), width (w), and height (h). Every corner angle is 90°.
Boxes are the most common shape in shipping, storage, and construction. Shoe boxes, shipping containers, rooms, aquariums, and refrigerators are all rectangular prisms.
Box volume = length × width × height (V = l × w × h).
For a box measuring 40 cm long × 30 cm wide × 20 cm tall:
V = 40 × 30 × 20 = 24,000 cm³ = 24 liters = 6.34 US gallons = 0.847 ft³.
This formula works for any rectangular container: fish tanks, shipping boxes, storage bins, and rooms.
Standard shoe box (33 × 19 × 12 cm): V = 33 × 19 × 12 = 7,524 cm³ = 7.52 L.
Internal: 5.9 × 2.35 × 2.39 m = 33.13 m³ = 33,130 L = 1,170 ft³.
122 × 33 × 46 cm = 185,196 cm³ ≈ 185.2 L ≈ 48.9 US gal (tank glass reduces usable volume).
A 5 × 4 × 2.7 m room: V = 54 m³ = 54,000 L = 1,907 ft³ (used for HVAC sizing).
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Answers to common questions about the box volume calculator.
Multiply length × width × height. Example: a box 50 cm × 40 cm × 30 cm = 60,000 cm³ = 60 liters. All three dimensions must be in the same unit before multiplying.
Measure the inside dimensions in inches or cm. Multiply l × w × h. For dimensional weight shipping: divide volume (in³) by the carrier's dim factor (usually 139 for domestic, 166 for international) to get billable weight in pounds.
A box (cuboid) can have different length, width, and height. A cube is a special box where all three dimensions are equal. Every cube is a box, but not every box is a cube.
1 cubic foot = 28.317 liters = 7.481 US gallons = 28,316.85 cm³.
If you know the volume and two dimensions, divide: missing dimension = V ÷ (known1 × known2). Example: 1,000 cm³ box that is 10 × 10 = height of 10 cm.