Geometry
Cubic Feet Calculator
Find the volume of a box, room, or cylinder in cubic feet — measure each side in inches, feet, yards, centimeters, or meters and mix them freely. Every conversion (yd³, m³, gallons, litres) and every step updates live.
Measure the space
L × W × HMix units freely — each field converts to feet before multiplying.
Volume
3
1.5 × 1.5 × 1.33 ft
Also equals
Cubic yards
0.111 yd³
Cubic meters
0.085 m³
Cubic inches
5,184 in³
Litres
84.95 L
US gallons
22.44 gal
US quarts
89.77 qt
inches or any unit
Try an example
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The basics
What is a cubic foot?
A cubic foot is the volume of a cube one foot on every side — the everyday unit for the capacity of fridges and freezers, the size of moving boxes and shipping crates, and bulk materials like mulch, soil, and concrete. Finding it always comes down to multiplying three lengths that share the same unit.
V = L × W × H
The box formula
For any rectangular space, multiply length by width by height. The answer is in cubic feet whenever each of L, W, and H is measured in feet.
2 ft × 3 ft × 4 ft = 24 ft³
V = π × r² × h
The cylinder formula
For a round tank, drum, or planter, square the radius (half the diameter), multiply by π, then by the height — every measurement in feet.
π × (1 ft)² × 3 ft ≈ 9.42 ft³
Method
How to calculate cubic feet by hand
Three steps for a box; the only discipline is making every dimension the same unit first.
- 1
Get every side into feet
If a measurement is in inches, divide by 12; in yards, multiply by 3; in centimeters, divide by 30.48. The three sides of L, W, and H must all be feet.
30 in ÷ 12 = 2.5 ft - 2
Multiply length × width × height
With every side in feet, multiply the three numbers together. The product is the volume in cubic feet.
2.5 × 2.5 × 5 = 31.25 ft³ - 3
Convert to the unit you need
Divide by 27 for cubic yards, multiply by 0.0283 for cubic meters, or multiply by 7.48 for US gallons.
31.25 ÷ 27 ≈ 1.16 yd³
Worked examples
See it across units and shapes
The same procedure handles feet, inches, mixed measurements, and round shapes — each tab computes the volume live from its dimensions.
Given A crate 4 ft × 3 ft × 2 ft
Convert to feet: L = 4 ft, W = 3 ft, H = 2 ft
Multiply L × W × H: 4 × 3 × 2
24 ft³0.889 yd³179.5 gal
Quick chart
How many cubic feet is X × Y × Z?
Common box and container sizes converted to cubic feet and cubic yards. Type your own dimensions in inches at the top to read the answer instantly.
Your size (inches):××=4.5 ft³
| Container | Inches (L×W×H) | Cubic feet | Cubic yards |
|---|---|---|---|
| Small moving box | 16 × 12 × 12 | 1.33 | 0.0494 |
| Medium moving box | 18 × 18 × 16 | 3 | 0.1111 |
| Large moving box | 18 × 18 × 24 | 4.5 | 0.1667 |
| Extra-large box | 24 × 18 × 24 | 6 | 0.2222 |
| Book / record box | 12 × 12 × 12 | 1 | 0.037 |
| Wardrobe box | 24 × 24 × 40 | 13.33 | 0.4938 |
| File box (banker’s) | 15 × 12 × 10 | 1.04 | 0.0386 |
| Postal flat-rate (large) | 12 × 12 × 6 | 0.5 | 0.0185 |
| Pallet (single layer) | 48 × 40 × 1 | 1.11 | 0.0412 |
| Cube — 1 ft | 12 × 12 × 12 | 1 | 0.037 |
| Cube — 2 ft | 24 × 24 × 24 | 8 | 0.2963 |
| Cube — 3 ft (1 yd³) | 36 × 36 × 36 | 27 | 1 |
Where it shows up
Where cubic feet matter
One measurement that drives appliance shopping, moving quotes, and material orders.
Capacity
Appliances
Refrigerators, freezers, and microwaves are rated by interior cubic feet — measure the inside to compare real usable space.
CBM / yd³
Moving & shipping
Movers and freight quotes price by volume. Cubic feet (and cubic meters for sea freight) decide how much truck or container you need.
÷ 27 → yd³
Landscaping & concrete
Mulch, topsoil, gravel, and concrete are ordered by the cubic yard, so a quick divide by 27 turns your cubic-foot figure into an order.
Reference
Cubic-foot conversions
What one cubic foot equals in the units you are most likely to need.
| From | To | Multiply by |
|---|---|---|
| 1 ft³ | cubic inches (in³) | 1,728 |
| 1 ft³ | cubic yards (yd³) | ÷ 27 |
| 1 ft³ | cubic meters (m³) | 0.0283168 |
| 1 ft³ | litres (L) | 28.3168 |
| 1 ft³ | US gallons | 7.48052 |
| 1 ft³ | US quarts | 29.9221 |
Worth knowing
Rules and pitfalls worth remembering
The handful of habits that keep cubic-foot answers correct.
Same unit first
Convert before you multiply
Mixing feet with inches in the same product gives nonsense. Get every side into one unit first — the tool does this automatically when you mix unit selectors.
÷ 1,728
Inches the fast way
Instead of converting each side, multiply the three inch measurements and divide by 1,728 — the number of cubic inches in a cubic foot.
Cube the conversion
Volume scales cubed
A yard is 3 feet, but a cubic yard is 3³ = 27 cubic feet. Linear factors always get cubed when you move to volume.
Inside, not outside
Measure the interior
For capacity — fridges, boxes, tanks — measure the inside dimensions. Outside measurements overstate how much actually fits.
r = d ÷ 2
Use radius, not diameter
The cylinder formula needs the radius. Halve the diameter before squaring, or you will overstate the volume four-fold.
ft³ ≠ ft²
Cubic is not square
Square feet measure area (two dimensions); cubic feet measure volume (three). If you multiplied only two sides, you found area, not volume.
Glossary
The terms in one place
Cubic foot (ft³)
The volume of a cube one foot on each side — the base unit this calculator reports.
Cubic yard (yd³)
The volume of a cube one yard on each side, equal to 27 cubic feet. The unit landscaping and concrete suppliers quote.
CBM (m³)
Cubic meter — the international shipping volume unit. One cubic meter is about 35.3 cubic feet.
Board foot
A lumber volume of 144 cubic inches (1 ft × 1 ft × 1 in), which is one-twelfth of a cubic foot — not the same as a cubic foot.
FAQ
Common questions
Measure length, width, and height in feet, then multiply all three: cubic feet = length × width × height. A box 2 ft × 3 ft × 4 ft holds 2 × 3 × 4 = 24 cubic feet. If a dimension is in another unit, convert it to feet before multiplying so all three share the same unit.
Divide each measurement in inches by 12 to get feet, then multiply the three feet values. For 24 in × 36 in × 48 in that is 2 × 3 × 4 = 24 cubic feet. Equivalently, multiply the three inch measurements and divide by 1,728 — the number of cubic inches in one cubic foot.
There are 27 cubic feet in one cubic yard, because a yard is 3 feet and 3 × 3 × 3 = 27. To convert cubic feet to cubic yards divide by 27; to go the other way multiply cubic yards by 27.
Measure its interior length, width, and height, convert each to feet, and multiply them. For a box measured in inches, divide each side by 12 first, or multiply the inches together and divide by 1,728. The result is the usable volume in cubic feet.
Measure the interior length, width, and height (usually in inches), convert each to feet, and multiply. A 30 in × 30 in × 60 in interior is 2.5 × 2.5 × 5 = 31.25 cubic feet — which is why fridges are sold by their cubic-foot capacity.
Use π r² h. Take half the diameter for the radius, square it, multiply by π (about 3.14159), then multiply by the height — all in feet. A drum 23 in across and 34 in tall is about 7.4 cubic feet, or roughly 55 US gallons.
One cubic meter equals about 35.315 cubic feet, and one cubic foot equals about 0.0283 cubic meters. Cubic meters (CBM) are the standard volume unit in international shipping, so converting between the two is common when quoting freight.
Multiply cubic feet by 7.48052 to get US liquid gallons, since one cubic foot holds 7.48052 gallons. For example, a 10-cubic-foot tank holds about 74.8 gallons. To reverse it, divide gallons by 7.48052.
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Ugo CharlesBuilt and fact-checked against our editorial standards · Last updated June 2026
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