EstimatorKitFree cubic feet calculator
Cubic feet from five shapes and any unit
Give the sides of a box, cylinder, cone, sphere or triangular prism and this returns the volume in cubic feet, plus the same quantity in cubic inches, cubic yards, cubic meters, US gallons and liters. Sides go in the way they were measured and can be mixed inside one shape, so 47 in, 2 ft 9 in and 0.9 m all belong on the same crate. Because a cubic foot is the unit printed on the front of a bag, it also shows how many 2, 1 and half cubic foot bags would fill the same space.
- 100% free
- No signup
- 5 shapes
- 5 input units
- 6 output units
Six flat sides: a freight crate, a truck bed, a chest freezer cavity, a form for a footing.
Mixing units in one box is fine: write 34 in against a side measured in feet, or 2' 7 1/2" for a crate that is neither.
Volume of this box
64 cu ft
- Cubic inches
- 110,592
- Cubic yards
- 2.37
- Cubic meters
- 1.81
- US gallons
- 479
- Liters
- 1,812
Filled from the shelf, that is
- 2 cu ft bags of mulch
- 32
- 1 cu ft bags of garden soil
- 64
- 0.5 cu ft sacks of sand or gravel
- 128
Bag sizes are the fixed retail products: the standard US retail mulch bag, the common retail bag of garden soil or compost, the common 50 lb retail bag of gravel or sand. Counts round up, because a store will not split one.
Cubic foot conversion table
Every figure below is fixed by definition rather than measured, so these are the same wherever you are and whatever is in the container.
| 1 cubic foot | 1,728 in³ · 0.0370 yd³ · 0.02832 m³ · 7.4805 US gallons · 28.317 liters |
|---|---|
| 1 cubic yard | 27 ft³ · 46,656 in³ · 0.7646 m³ · 201.97 US gallons · 764.55 liters |
| 1 cubic meter | 35.315 ft³ · 1.3080 yd³ · 61,024 in³ · 264.17 US gallons · 1,000 liters |
| 1 US liquid gallon | 0.13368 ft³ · 231 in³ exactly · 3.7854 liters |
| 1 liter | 0.035315 ft³ · 61.024 in³ · 0.26417 US gallons |
| 1 cubic inch | 0.00057870 ft³ · 16.387 cm³ |
| 1 board foot | 0.08333 ft³ · 144 in³ — one inch thick, one foot square |
How to calculate cubic feet
Three steps, and the first one decides whether the answer is right by a factor of three.
Pick the solid you are actually looking at
A crate and a freezer cavity are boxes; a sonotube, a drum and a culvert are cylinders; a tipped stockpile is a cone; the wedge behind a ramp or under a gable is a triangular prism. Choosing the right one matters more than the arithmetic does — a cone measured as a cylinder comes out three times too big, which is the single most common way a pile gets over-ordered.
Type each side in whatever unit it was measured in
Set what a bare number means — feet, inches, yards, meters or centimeters — then override it per field by writing the unit. A crate measured 47 in long, 2 ft 9 in wide and 0.9 m tall goes in exactly like that, with no conversion done in your head first. Round shapes want the diameter measured straight across the widest point, not a tape run around the outside.
Read the volume, then take the unit you need it in
Cubic feet comes first because that is the unit on a bag, a freight tariff and an appliance spec sheet. The same figure is repeated in cubic inches, cubic yards, cubic meters, US gallons and liters, and underneath it the number of 2, 1 and half cubic foot bags it would take to fill the space. Copy gives you all of it as plain text.
Technical specifications
| Shapes | Box, cylinder, cone, sphere and triangular prism — five solids, no sub-menus |
|---|---|
| Bare-number unit | Feet, inches, yards, meters or centimeters, chosen once for the form |
| Per-field override | Write the unit and it wins: 34 in, 2' 7 1/2", 3/4 ft, 0.9 m, 90 cm |
| Output units | Cubic feet, cubic inches, cubic yards, cubic meters, US gallons, liters |
| Cubic inches per cubic foot | 1,728 — 12³, definitional rather than measured |
| US gallons per cubic foot | 7.480519, from the gallon's definition of 231 cubic inches |
| Bag equivalents | 2 ft³ mulch bags, 1 ft³ soil bags and 0.5 ft³ sacks, rounded up to whole bags |
| Stored or sent | Nothing — the sides you type stay in the tab and vanish on reload |
Frequently asked questions
How many cubic inches are in a cubic foot?
1,728. A foot is 12 inches, and volume goes with the cube, so it is 12 × 12 × 12 rather than anything you need to look up. The same relationship catches people out in the other direction: a cube twice as wide holds eight times as much, not twice as much.
Can I measure a round tank or tube without getting a tape across it?
Measure around it and divide by 3.1416. A tape run round the outside gives the circumference, and dividing by pi gives the diameter this calculator asks for — a 94 in girth is a 30 in tube. Getting a rigid rule across the mouth of a pipe is usually harder than wrapping a tape round it, and the arithmetic is exact either way.
Why is a cone one third of a cylinder rather than one half?
Because the radius shrinks all the way down, not linearly in area. The cross-section of a cone falls with the square of the height, so integrating it gives a third, which is why a stockpile that looks like it half fills its footprint holds far less than the eye reports. It is the reason a tipped load looks like more material than the ticket says.
Does a cubic foot of loose material fill a one cubic foot bag?
No, and the gap is real. Bagged material is measured at the packing line, where it is dropped in loose; the same product settles in the bag on the pallet and again when you dump it, so the space it fills on your job is a little less than the printed figure. It is a small effect for gravel and a noticeable one for shredded bark, which is why bag counts here round up.
What is the volume in cubic feet of a standard shipping pallet load?
A 48 × 40 in pallet stacked 48 in high is 53.3 cubic feet: 4 ft × 3.333 ft × 4 ft. That is the figure freight tariffs quote for a full pallet, and it is worth knowing because carriers price on the greater of actual weight and volume — a light, bulky load pays for the space it occupies rather than what it weighs.
The tool gives me a volume — how do I get the weight?
It deliberately does not, because a cubic foot has no weight until you say what is in it. Water is 62.4 lb per cubic foot, dry sawdust is nearer 12, and hot mix asphalt is over 145. The conversion for the materials this site deals with lives on the tons to cubic yards page, where each one carries its own density and the range that density really moves over.
About the cubic foot
The cubic foot is the unit American products are packaged and rated in. A bag of mulch says 2 ft³ on the front, a chest freezer is sold as 7.1 ft³, an air compressor is rated in cubic feet per minute and a freight quote is priced on the cube it occupies. That is why it is worth calculating directly rather than as a stop on the way to something else: for a very large share of these searches the cubic foot figure is the answer, not an intermediate. It is also small enough to describe an appliance and a crate without decimals running away, which cubic yards cannot do.
The mistakes are geometric rather than arithmetic. A tape wrapped around a tube gives circumference, and using it as a diameter overstates the volume by a factor of ten. A tipped pile is a cone and holds a third of the cylinder it appears to fill. A sphere is πd³ divided by six, so the ball that looks twice as big as another holds eight times as much. None of that is difficult, but all of it happens before any multiplication does, which is why this tool asks you to name the solid first and only then asks for numbers. The other habit worth having is measuring the inside: a container’s outside dimensions include walls that hold nothing.
Cubic feet stops being the useful unit at roughly the point a wheelbarrow does. Past about twenty of them nobody sells the material by the bag any more, and the conversation switches to the cubic yard calculator and a truck. If what you have is a surface rather than a solid — a patio, a bed, a driveway — the missing number is a thickness, and square feet to cubic yards asks for it directly. From there the material pages take over: bedding depths on the sand calculator and the migration problem that decides edging on pea gravel.
Where the dimensions you type go
Every number on this page is worked out by JavaScript running in the tab you are reading it in. Nothing you type — measurements, quantities, the prices your supplier quoted you — is uploaded, logged or kept, which is also why the calculators carry on working on a site with no signal.
There is nothing to store here anyway — no saved shapes, no history, no account. Reload the page and it comes back to the same 8 × 4 × 2 box everyone else sees.