Cubic Feet Calculator

Calculate the cubic feet of a box, appliance or room from its length, width and height in inches or feet, with the volume in cubic inches, cubic yards and gallons.

By CalcBuilt Editorial TeamUpdated September 13, 2026Formulas checked against manufacturer specs, see how we calculate.

Quick answer: To calculate cubic feet, multiply length by width by height in inches and divide by 1,728, or multiply the three dimensions in feet directly. A 24 x 18 x 12 in box is 5,184 cubic inches, or 3 cubic feet, which holds 22.44 gallons.

Results

Cubic feet: 3 cu ft; 24 in x 18 in x 12 in
Cubic inches: 5,184 cu in; 1 cubic foot = 1,728 cubic inches
Cubic yards: 0.111 cu yd; 1 cubic yard = 27 cubic feet
US gallons: 22.44 gal; 1 cubic foot = 7.48 US gallons
Weight of water if filled: 187.2 lb; At 62.4 lb per cubic foot

Cubic Feet formula

Cubic inches = Length (in) x Width (in) x Height (in) x quantity
Cubic feet = Cubic inches / 1,728  (or Length (ft) x Width (ft) x Height (ft))
Cubic yards = Cubic feet / 27;  Gallons = Cubic feet x 7.48
Water weight (lb) = Cubic feet x 62.4

Worked example

Three storage totes, each 36 x 24 x 20 in: 36 x 24 x 20 = 17,280 cubic inches each. 17,280 / 1,728 = 10 cubic feet, so the three totes are 30 cubic feet, or 1.11 cubic yards. Filled with water they would hold 30 x 7.48 = 224.4 gallons and weigh 30 x 62.4 = 1,872 lb.

The same answer in feet: 3 ft x 2 ft x 1.667 ft = 10 cubic feet per tote. Switch the calculator to feet to enter dimensions that way; it multiplies by 12 behind the scenes.

Quick reference

How big is a cubic foot: common volumes and what each one looks like
Cubic feet	What that looks like	Dimensions	US gallons
1	A 12 in cube, or a 1 cu ft bag of garden soil	12 x 12 x 12 in	7.5
1.45	A small moving box, or a bag of potting mix	16 x 12.5 x 12.5 in	10.8
2	A standard bag of bark mulch	24 x 12 x 12 in	15.0
3	A medium moving box	18 x 18 x 16 in	22.4
4.5	A large moving box	18 x 18 x 24 in	33.7
6	An extra large box, or a contractor wheelbarrow	24 x 18 x 24 in	44.9
9	The inside of a small chest freezer	30 x 18 x 29 in	67.8
10	One large storage tote	36 x 24 x 20 in	74.8
11.67	A dishwasher, outside	24 x 24 x 35 in	87.3
16.45	A washer, outside	27 x 27 x 39 in	123.0
27	One cubic yard	36 x 36 x 36 in	202.0
43.75	A full size refrigerator, outside	36 x 30 x 70 in	327.2

How to calculate cubic feet

Cubic feet is length times width times height with all three in feet. Most things you measure are in inches, so multiply the three inch dimensions together for cubic inches and divide by 1,728, which is 12 x 12 x 12. A 24 x 18 x 12 inch box is 5,184 cubic inches, or 3 cubic feet. Converting each dimension to feet first (2 x 1.5 x 1) gives the same 3 cubic feet.

For mixed measurements such as 4 ft 6 in, convert to decimal feet (4.5) or to inches (54) before multiplying. For a cylinder such as a drum or tank, use radius squared times 3.1416 times height instead of length times width.

Where cubic feet show up

Movers and truck rentals size loads in cubic feet and figure about 7 lb per cubic foot for household goods. A one-bedroom apartment is roughly 400 to 600 cubic feet of boxes and furniture, and a three-bedroom house 1,200 to 1,800, which fills a 26 ft truck once pads and gaps take their 15 percent. Books run 40 lb per cubic foot, so they go in 1.5 cubic foot boxes, and a 10 ft rental carries only about 2,800 lb of payload. Appliances are rated by interior capacity, which is smaller than the box they ship in: a 25 cubic foot refrigerator is about 36 x 30 x 70 in outside, 44 cubic feet. Measure the outside for the truck and the cabinet opening. Measure the door path at the stops with the fridge doors and handles off.

Shipping carriers charge by dimensional weight, cubic inches divided by 139, so a 3 cubic foot box bills as 37 lb however light it is. LTL freight classes by density, pounds divided by cubic feet: a 4 lb per cubic foot pallet ships at class 200 and 15 lb per cubic foot at class 70. Freezers, water heaters and aquariums are sized in cubic feet or gallons; multiply cubic feet by 7.48 to move between the two. A 100 gallon aquarium holds 834 lb of water before the tank and stand.

What this calculator leaves out

Packing paper and pads, which take 10 to 15 percent of truck volume. The truck's payload limit, about 2,800 lb for a 10 ft rental and 9,000 lb for a 26 ft. Appliance delivery, hookup and haul-away fees, typically $25 to $50 for the old unit. The room an appliance needs once it lands. A refrigerator wants about 1 in of air at the back and top and a door swing clear of the adjacent wall; a dryer needs 4 to 6 in behind it for the vent elbow.

Mistakes that cost money

Doorway measured frame to frame: a 32 in door leaves 30-1/2 in clear at the stops; a full-depth fridge passes only with its doors off.
Trusting the capacity rating: a 25 cu ft refrigerator is about 44 cu ft outside, and the truck, doorway and cabinet opening see the outside.
A 4.5 cu ft box of books weighs 180 lb and the bottom drops out; pack books in 1.5 cu ft book boxes.
Sizing the truck by box count: a sofa is 60 to 80 cu ft, a queen mattress set 60, pads and gaps 15 percent more.
Shipping air: carriers bill cubic inches divided by 139 as pounds, so a 24 x 18 x 12 in box bills as 37 lb.
A 10 x 10 storage unit is 800 cu ft on paper and holds about 500 with an aisle and a 6 ft stack.

Key facts

One cubic foot is 1,728 cubic inches, 7.48 US gallons, 28.32 liters, or 0.037 cubic yards.
A cubic foot of water weighs 62.4 lb, so a 40 gallon water heater holds about 334 lb of water.
A medium moving box (18 x 18 x 16 in) is 3 cubic feet; a large box (18 x 18 x 24 in) is 4.5 cubic feet.
Refrigerator and washer sizes are interior capacity: 20 to 25 cubic feet for a full-size fridge and 4 to 5 cubic feet for a washer drum.
Rental trucks are rated by cargo volume: about 400 cubic feet for a 10 ft truck, 760 for a 15 ft truck and 1,700 for a 26 ft truck.

Frequently asked questions

How do I calculate cubic feet from inches?

Multiply length x width x height in inches, then divide by 1,728. A 24 x 18 x 12 in box is 5,184 cubic inches, or 3 cubic feet.

How big is 3 cubic feet?

About the size of a medium moving box, 18 x 18 x 16 in, holding 22.4 gallons. For scale: 1 cubic foot is a 12 in cube, 2 cubic feet is a bag of mulch, 6 is a contractor wheelbarrow, 10 is a large storage tote and 27 is a full cubic yard.

Will a new refrigerator fit through my door?

Measure the clear opening at the door stops, not the frame: a 32 in door gives about 30-1/2 in and a 30 in door about 28-1/2 in. A standard-depth refrigerator is 33 to 36 in deep with the doors on and 28 to 30 in with them off. It passes a 32 in door on its side with the doors and handles pulled. A counter-depth model at 24 to 27 in deep goes through as is. Check the hallway turn and the cabinet opening too: a 36 in fridge wants 36-1/4 in of width, 70 to 72 in of height and about 1 in of air behind it.

How many gallons are in a cubic foot?

7.48 US gallons. A 3 cubic foot container holds 22.44 gallons, and a cubic foot of water weighs 62.4 lb.

How many cubic feet is a 12 x 12 room with an 8 ft ceiling?

12 x 12 x 8 = 1,152 cubic feet. Switch the calculator to feet and enter 12, 12 and 8 to get the same result.

Sources and references

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Results are estimates based on standard formulas and typical product specifications. Confirm quantities with your supplier and local code before ordering.