Cubic Feet Calculator

Volume (ft³) = length (ft) × width (ft) × height (ft), and 1 ft³ = 0.037037 yd³ = 28.3168 litres = 0.0283168 m³

L

Length of the box, room or crate in feet — the page converts whatever unit you pick into feet first

W

Width, in the same unit as the length

H

Height: the third side, measured inside for a container and floor to ceiling for a room

× 0.037037

Cubic yards in a cubic foot — 1 ÷ 27. The unit gravel, soil and concrete are sold in

× 28.3168

Litres in a cubic foot, the unit a bag of soil or a tank is labelled in

× 0.0283168

Cubic metres in a cubic foot, for freight, storage and anything quoted metrically

Use it when a volume has to match something that is already labelled in a particular unit: whether a fridge or a freezer is big enough for the space you have, how many cubic feet of goods will go in a storage unit, what a shipping crate measures for a freight quote, or how many bags of mulch fill a raised bed. It is also the page for the volume of a room when you are sizing a heater, an air conditioner or a dehumidifier, all of which are rated by the volume they handle. If what you are measuring is a slab, a trench or a footing — a footprint times a thickness rather than a box with a height — the cubic yards calculator is the right page, because that is the shape concrete is ordered in. If it is a cylinder, a tank or a pipe, the tank volume calculator takes a diameter instead of a width.

1. A 4 × 3 × 2 ft crate — the page's default

   1. Volume: 4 × 3 × 2 = 24 ft³
   2. In cubic yards: 24 ÷ 27 = 0.89 yd³
   3. In litres: 24 × 28.3168 = 679.6 L
   4. In cubic metres: 24 × 0.0283168 = 0.68 m³

   24 cubic feet is the size of a large appliance carton, and one person can still carry it empty. The four lines are one volume written four ways rather than four answers: a cubic foot is exactly 1 ÷ 27 of a cubic yard and exactly 0.0283168 of a cubic metre, so the only difference between the lines is how many digits each was rounded to. That matters when you compare against a number someone else gave you — a skip quoted as 0.89 cubic yards, a fridge rated at 24 cubic feet and a crate measured at 0.68 cubic metres are all the same size of hole.

2. A 12 × 10 × 8 ft room

   1. Volume: 12 × 10 × 8 = 960 ft³
   2. In cubic yards: 960 ÷ 27 = 35.56 yd³
   3. In cubic metres: 960 × 0.0283168 = 27.184 m³

   A room belongs on this page as much as a box does, because that is the calculation behind every heater, air conditioner and dehumidifier rating: they are sized by the volume of air they have to treat, not by floor area. This is the same room the CFM calculator works from, and the two pages are meant to be used together — this one gives the volume, and that one multiplies it by the air changes per hour to get the airflow. The ceiling height is the input people guess at, and it is also the one that moves the answer most: an eight foot ceiling is the default, but a basement room at seven feet is 12% less air than the same footprint upstairs.

3. An 18 × 24 × 12 in moving box

   1. In feet: 18 in = 1.5 ft, 24 in = 2 ft, 12 in = 1 ft
   2. Volume: 1.5 × 2 × 1 = 3 ft³
   3. In cubic yards: 3 ÷ 27 = 0.11 yd³
   4. In cubic metres: 3 × 0.0283168 = 0.085 m³

   This is the box the packaging trade calls a three cubic foot carton, and it is the second row of the table below — which is the point of the example: the table and the calculator are the same arithmetic, so the 3 in the table and the 3 here cannot disagree. It is also the size most moving companies use as their unit of account, which is why a quote for a house move arrives as a number of boxes rather than as a volume, and why knowing that one of them is three cubic feet is enough to sanity check the total.

This is geometry, so the answer is exact for whatever dimensions you give it — and the dimensions are where all the error is. For a container, measure the inside: a crate's outside is bigger by the thickness of its walls, and a fridge rated at 25 cubic feet is smaller than the box it arrived in, because the appliance rating counts usable space and this page counts the envelope. For a room, floor to ceiling is rarely one number — a suspended ceiling, a bulkhead or a duct soffit takes volume out, and using the structural height overstates the room by a few percent. The page also assumes a rectangular prism: a tapered, sloped or L-shaped space has to be split into pieces and added up, and a cylinder or a cone is a different formula entirely. Finally, a volume is not a capacity you can fill: the same 50 cubic feet of pickup bed holds less when the goods are boxes rather than sand, because the space between them counts for nothing here.

How do I work out cubic feet?

Multiply the three dimensions together, all in feet: a box 4 feet by 3 feet by 2 feet is 4 × 3 × 2 = 24 cubic feet. If your measurements are in inches, either convert them to feet first by dividing by 12 or multiply the inches together and divide by 1,728, which is 12 cubed. The one thing to watch is using the same unit for all three sides — 4 feet by 3 feet by 12 inches is not 144 of anything until the 12 inches becomes 1 foot.

How many cubic feet is a refrigerator?

A large fridge-freezer is 25 cubic feet of usable space, which is the row in the table above; a small under-counter model is nearer 5. That figure is measured inside, and it counts only the space you can put food in, so the outside of the same appliance is noticeably bigger — measure the niche with a tape before you buy, because a 25 cubic foot fridge will not go into a 25 cubic foot gap. The litre figure is on the label too, usually 400 to 700 for a domestic model, and one cubic foot is 28.3 litres.

How many litres are in a cubic foot?

28.3168, so a two cubic foot bag of mulch or potting soil is 56.6 litres and a five gallon bucket is 0.67 cubic feet. The conversion is exact rather than approximate because the litre is defined as one cubic decimetre, so 1 cubic foot is 28.316846592 litres. That is why the table below carries both columns and why they always agree: they are one volume, written for two different labels.

Is this the same as the cubic yards calculator?

The arithmetic is the same and the shape is not. That page multiplies a length and a width by a thickness in inches, which is a slab, a trench or a footing, and it reports cubic yards because concrete, gravel and topsoil are ordered that way. This page multiplies three lengths and calls the third one a height, which is a box, an appliance or a room, and it reports cubic feet because that is how those things are labelled. Confusing the two costs a factor of 27 — 27 cubic feet is a cubic yard — so the test is what the thing is bought as, not which unit you happen to have measured in.

How do I convert cubic feet to cubic metres?

Multiply by 0.0283168, or divide by 35.3147. A 24 cubic foot crate is 0.68 cubic metres, and a 20 foot shipping container holds about 33 cubic metres, or 1,165 cubic feet. Metric quotes for freight and storage are almost always in cubic metres, so the line is worth reading before you compare two prices. Note that the cubic metre line on this page is rounded to three decimals rather than two, on purpose: a small box is a few thousandths of a cubic metre, and two decimals would round it away.

How many cubic feet is a mulch bag?

Two cubic feet is the standard bag for mulch, compost and potting soil, and it is 56.6 litres — the first row of the table. It is sold by volume rather than by weight because a bag settles and its water content changes, so the number on the front is the one to work from: a raised bed 4 feet by 8 feet filled 6 inches deep is 16 cubic feet, which is eight bags. Bulk mulch is sold by the cubic yard instead, and one cubic yard is 13.5 of those bags.

• Approximate Conversions from U.S. Customary Measures to Metric — the chart behind the cubic foot, the cubic yard and the litre figures used here — National Institute of Standards and Technology
• The International System of Units (SI) brochure — the metre and the cubic metre, and the definition of the litre as exactly one cubic decimetre — Bureau International des Poids et Mesures (BIPM)