CalcRover

Cubic Feet Calculator

Multiply length × width × height to get cubic feet — with each dimension entered in inches or feet, whichever you measured. Results come with cubic yards (for ordering materials) and cubic inches (for shipping specs).

Length
Width
Height

Cubic feet formula

Convert every dimension to feet first (inches ÷ 12), then multiply the three together. The classic mistake is multiplying inches directly and dividing by 12 — volume needs the cube: there are 12³ = 1,728 cubic inches in a cubic foot, not 12.

Useful anchors: a cubic yard is 27 cu ft; a standard bathtub holds ~13 cu ft of water; a 10 × 10 × 8 ft storage room is 800 cu ft. Freight and appliances (refrigerators, ovens) are specced in cubic feet, which is why mixed inch/foot inputs matter.

cu ft = L(ft) × W(ft) × H(ft)
inches ÷ 12 → feet; cu ft × 1,728 = cu in; cu ft ÷ 27 = cu yd

Worked examples

Example 1: moving box in inches

A box 24 × 18 × 18 inches — how many cubic feet?

  1. Convert to feet.
    2 × 1.5 × 1.5 ft
  2. Multiply.
    2 × 1.5 × 1.5 = 4.5 cu ft

4.5 cubic feet — a standard "large" moving box.

Example 2: mulch for a raised bed

A 6 ft × 3 ft bed, filled 10 in deep.

  1. Depth to feet.
    10 ÷ 12 = 0.833 ft
  2. Volume.
    6 × 3 × 0.833 = 15 cu ft
  3. Bags of mulch come in 2 cu ft.
    15 ÷ 2 = 7.5 → 8 bags

15 cu ft — eight 2-cu-ft bags.

Example 3: why inches × inches × inches ÷ 12 is wrong

A 12 × 12 × 12 inch cube.

  1. Correct: convert first.
    1 × 1 × 1 = 1 cu ft
  2. Wrong shortcut.
    12 × 12 × 12 ÷ 12 = 144 — off by 144×

Exactly 1 cu ft; divide cubic inches by 1,728, never by 12.

FAQ

How many cubic feet are in a cubic yard?+

27 (3 × 3 × 3). Mulch, soil and concrete are quoted per cubic yard; divide your cubic feet by 27 to order.

How do I convert cubic feet to gallons or liters?+

1 cu ft ≈ 7.48 US gallons ≈ 28.32 liters. For tanks and aquariums, our volume calculator does this directly, including cylinders.

What does "cu ft" mean on a refrigerator?+

Interior storage volume — US fridges run 10–28 cu ft, microwaves 0.7–2.2. It's measured on the usable inside space, not the appliance's outer box.

Can I mix units like 6 ft by 30 in?+

Yes — that's this calculator's whole point: each dimension has its own in/ft selector, and the steps show each conversion before multiplying.

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