📦 Cubic Feet Calculator
Find the volume of any box, cylinder, or prism in cubic feet — plus cubic inches, cubic yards, cubic meters, gallons, and liters. For shipping, storage, moving, and tanks. Free, no sign-up.
A cubic feet calculator finds the volume of a three-dimensional object — a box, a cylinder, or a prism. It converts your length, width, and height into cubic feet and shows the same volume in cubic inches, cubic yards, cubic meters, US gallons, and liters. The standard formula for a box is:
How to calculate cubic feet in 3 steps:
- Pick a shape — box, cylinder, or triangular prism — and choose whether you measured in feet or inches.
- Enter the dimensions: length, width, and height for a box; diameter and height for a cylinder.
- Click Calculate Volume to see cubic feet, cubic inches, cubic yards, cubic meters, gallons, and liters.
For example, a box 3 ft × 3 ft × 3 ft holds 3 × 3 × 3 = 27 cubic feet — which is exactly 1 cubic yard. That same volume equals 46,656 cubic inches, about 0.76 cubic meters, or roughly 202 US gallons.
Cubic Feet Calculator
Pick a shape, enter dimensions, see the volume in six units instantly.
From Boxes to Tanks –
One Tool for Every Cubic-Feet Question
Shipping a package, sizing a storage unit, filling a tank, comparing appliances — they all come down to cubic feet. This free calculator turns the dimensions of a box, cylinder, or prism into volume in six units at once, with feet or inches input.
⚡ Try the Calculator NowCubic Feet: The Volume Unit Behind Shipping, Storage & More
A cubic foot is the volume of a cube one foot on every side. It is the unit that quietly runs a surprising amount of everyday life — what a moving company quotes you, how a carrier prices a bulky package, how big a refrigerator or storage unit really is, and how much water a tank holds.
The math for a box is simple — length times width times height. The part people stumble on is units. Boxes are usually measured in inches, but the answer is wanted in cubic feet, and the conversion is not a simple divide-by-twelve: there are 1,728 cubic inches in a cubic foot, not 12. Mixing that up is the single most common cubic-feet mistake.
This free Cubic Feet Calculator removes the guesswork. Pick a box, cylinder, or triangular prism, enter the dimensions in feet or inches, and it returns the volume in cubic feet, cubic inches, cubic yards, cubic meters, gallons, and liters at once.
How the Cubic Feet Calculator Works
Choose a shape, set the unit, enter the dimensions, and click once. The calculator returns the volume in six units plus a breakdown with extra space. Here is what each control does.
Pick the Shape
Box covers crates, cartons, rooms, and storage units. Cylinder handles tanks, drums, columns, and round containers. Triangular prism covers wedge shapes — ramps, firewood racks, and angled spaces.
Choose Feet or Inches
Use the unit toggle to match how you measured. Small items — boxes, parcels, drawers — are usually measured in inches. Rooms and large objects in feet. The calculator handles the conversion either way.
📐 Keep all three dimensions in the same unit.Enter the Dimensions
For a box, enter length, width, and height. For a cylinder, the diameter and the height. For a triangular prism, the triangle's base and height plus the length of the prism.
Enter the Number of Items
Measuring several identical objects — a stack of moving boxes, a row of drums? Enter the count and the calculator totals them. For a single object, leave this at 1.
📦 This is the fast way to size a whole move.Add Extra Space (Optional)
In Advanced mode, add an extra-space margin for packing material, air gaps, or ordering headroom. You can also enter a price per cubic foot if you have a freight or material rate.
Hit Calculate — Read Every Unit
Instantly see the volume in cubic feet, cubic inches, cubic yards, cubic meters, US gallons, and liters, plus the total with extra space.
✅ Box formula: Volume = Length × Width × HeightThe Cubic Feet Formula, Explained
Each shape has one exact formula. The only real complication is the inches-to-feet conversion — and it is not the one most people expect.
Box: Volume equals length times width times height, with all three in feet. A box 4 feet long, 3 feet wide, and 2 feet tall holds 4 × 3 × 2 = 24 cubic feet. A cube is just a box where all three sides are equal.
The inches trap: If you measured in inches, you cannot simply divide by 12. There are 1,728 cubic inches in a cubic foot, because a cubic foot is 12 × 12 × 12 inches. So multiply the three inch dimensions together and divide by 1,728. A box 24 inches on every side is 24 × 24 × 24 = 13,824 cubic inches, which is 13,824 ÷ 1,728 = 8 cubic feet. This calculator does the division automatically when you select the inches unit.
Cylinder: Volume equals π (about 3.14159) times the radius squared, times the height. The radius is half the diameter. For a tank 2 feet across and 4 feet tall, the radius is 1 foot, so the volume is 3.14159 × 1 × 1 × 4 ≈ 12.6 cubic feet.
Triangular prism: Volume equals the area of the triangular end — half the base times the height — multiplied by the length of the prism. A prism with a 4-foot base, a 3-foot triangle height, and an 8-foot length holds 0.5 × 4 × 3 × 8 = 48 cubic feet.
Volume Unit Conversions Worth Knowing
A cubic-feet figure rarely stands alone. Carriers, suppliers, and spec sheets each use their own unit, and these factors connect them all.
| Conversion | Multiplier | When You Use It |
|---|---|---|
| Cubic inches → cubic feet | ÷ 1,728 | Turning a box measured in inches into cubic feet |
| Cubic feet → cubic inches | × 1,728 | Working with small-item or precision volumes |
| Cubic feet → cubic yards | ÷ 27 | Comparing against bulk material sold by the yard |
| Cubic feet → cubic meters | × 0.02832 | Metric specs and international shipping |
| Cubic feet → US gallons | × 7.48 | Tanks, aquariums, and water capacity |
| Cubic feet → liters | × 28.32 | Metric liquid capacity |
The conversions in plain language: There are 1,728 cubic inches and about 7.48 US gallons in a cubic foot, and 27 cubic feet in a cubic yard. One cubic foot is a little over 28 liters, or about 0.028 cubic meters. The inch and yard conversions come up most often — the first for measuring, the second for comparing to bulk material.
Quick Reference: Common Cubic-Feet Volumes
| Object | Typical Volume | Notes |
|---|---|---|
| 📦 Small moving box | ~1.5 ft³ | Books, small heavy items |
| 📦 Medium moving box | ~3 ft³ | The all-purpose box |
| 📦 Large moving box | ~4.5 ft³ | Bulky, lightweight items |
| 🧺 Standard washing machine | ~4–5 ft³ | Drum capacity |
| ❄️ Household refrigerator | ~18–28 ft³ | Fridge plus freezer |
| 🚪 Small storage unit (5×5) | ~200 ft³ | 5 ft × 5 ft × 8 ft tall |
Factors That Affect Your Volume Measurement
The formula is exact, but a few real-world details decide whether the number you get is the number you need.
The Three Shapes Compared
Almost any object can be measured as one of these three shapes — or built from a combination of them.
| Shape | What You Measure | Use It For | Watch Out For |
|---|---|---|---|
| Box | Length, width, height | Cartons, crates, rooms, storage units, drawers | Inside vs outside dimensions |
| Cylinder | Diameter and height | Tanks, drums, columns, pipes, round planters | Measuring radius instead of diameter |
| Triangular Prism | Triangle base, triangle height, prism length | Ramps, firewood racks, wedge-shaped spaces | Using the slanted side as the height |
| Combination | Each part separately | Stepped or compound objects | Overlapping or skipping sections |
How to Measure Volume, Step by Step
A reliable volume measurement follows the same four phases whether you are sizing one parcel or a whole moving truck.
Look at the object and match it to a box, a cylinder, or a prism. If it does not fit one cleanly, sketch it and split it into simple shapes. Getting this right first prevents using the wrong formula later.
Decide upfront whether you will measure in feet or inches, based on the object's size, and use that unit for every dimension. For shipping, decide whether you need inside or outside measurements before you start.
Take each dimension at its widest, including bulges and protrusions if the volume is for shipping. For a cylinder, measure the diameter across the true center. For shipping, round each measurement up to the next whole unit.
Enter each shape into the calculator, note its cubic feet, and add the parts for a grand total. For multiple identical items, use the quantity field. Add an extra-space margin if you are planning packing or storage.
Cubic Feet in Shipping & Storage
Cubic feet is not just a geometry exercise — it directly drives what you pay to ship and store things. Here is how the number is used in the real world.
In shipping, carriers use volume to calculate dimensional weight: a billable weight derived from how much space a package takes up. A large, light box can be charged as if it were much heavier, because it occupies room that could carry denser freight. Knowing the cubic feet of a shipment is the first step in predicting that charge.
| Use Case | Why Cubic Feet Matters | What to Measure |
|---|---|---|
| Parcel shipping | Sets dimensional weight and the billed rate | Outside dimensions, rounded up |
| Moving a home | Determines truck size and the mover's quote | All boxes and furniture, totaled |
| Renting storage | Decides which unit size fits your goods | Total volume of everything stored |
| Buying an appliance | Compares fridge, freezer, or washer capacity | Interior dimensions or the spec sheet |
| Filling a tank | Converts to gallons or liters of capacity | Interior diameter and height |
Example Cubic Feet Calculations
Three objects, three shapes — each worked through with verified math so you can sanity-check your own results.
Getting an Accurate Cubic Feet Figure Every Time
Accuracy comes from method. These habits separate a volume you can ship or store against from a guess that costs money.
The most consequential decision is inside versus outside dimensions. They answer different questions: outside dimensions tell a carrier how much space a package occupies; inside dimensions tell you how much it can hold. Using the wrong one is the difference between an accurate shipping estimate and an accurate capacity estimate — and they are not interchangeable.
The second habit is unit discipline. Because volume multiplies three numbers, a single dimension left in the wrong unit throws the whole result off by a wide margin. Decide on feet or inches before you start, and convert everything to it first.
Six Habits for a Reliable Volume
When This Calculator Is the Wrong Tool
The three shapes cover most volume problems, but not every one. Here are the situations where the result needs care or a different tool.
1. Free-form and curved shapes. A sphere, a cone, a dome, or an organic shape is not a box, cylinder, or prism. Approximate it by splitting it into shapes you can measure, or use a formula specific to that shape. The closer your approximation, the better the estimate.
2. Exact dimensional-weight billing. This calculator gives you the cubic feet of a shipment, which is the input to dimensional weight — but each carrier uses its own divisor and rounding rules. For an exact billed figure, apply your carrier's published dimensional-weight formula to the measurements.
3. Usable capacity of a packed space. The geometric volume of a truck, container, or storage unit is the maximum, not the practical capacity. Real packing leaves gaps around irregular items, so usable capacity is typically 10–25% less than the calculated volume.
4. Volume that needs a weight. Cubic feet measures space only. To know what a volume weighs — for hauling limits or freight class — you need the material's density. For bulk landscape materials, a cubic yard calculator that includes weight is the better fit.
Where to go instead: For bulk material sold by the cubic yard, with weight and bag counts, use a cubic yard calculator. For the flat area of a surface before any depth, a square footage calculator is the first step. This tool's strength is being the fast, accurate answer to "how many cubic feet."
Cubic Feet Terms You'll See On This Page
Quick reference for the volume terms used throughout this calculator.
- Cubic Foot (ft³)
- The volume of a cube one foot on each side. The standard US unit for shipping volume, appliance capacity, and storage space.
- Cubic Inch (in³)
- The volume of a cube one inch on each side. There are 1,728 cubic inches in a cubic foot.
- Cubic Yard (yd³)
- The volume of a cube three feet on each side, equal to 27 cubic feet. Used for bulk landscape and construction material.
- Cubic Meter (m³)
- The metric volume unit, equal to about 35.31 cubic feet. The standard volume unit outside the US.
- Volume
- The amount of three-dimensional space an object occupies or contains.
- Box (Rectangular Prism)
- A six-sided shape with rectangular faces. Its volume is length times width times height.
- Cylinder
- A round shape with a circular cross-section and a constant height. Its volume is π times the radius squared, times the height.
- Triangular Prism
- A shape with a triangular cross-section running a constant length. Its volume is the triangle's area times the length.
- Diameter
- The distance straight across a circle through its center. The radius — used in the cylinder formula — is half the diameter.
- Dimensional Weight
- A billable weight that carriers derive from a package's volume, so light but bulky shipments are priced for the space they use.
- Density
- The weight of a material per unit of volume. Density is what turns a volume in cubic feet into a weight.
- Inside vs Outside Dimensions
- Outside dimensions give the space an object occupies; inside dimensions give what it can hold. They differ by the wall thickness.
- US Gallon
- A unit of liquid volume; one cubic foot holds about 7.48 US gallons. Used for tank and aquarium capacity.
- Extra-Space Margin
- A percentage added to the geometric volume to allow for packing material, air gaps, and practical headroom.
Frequently Asked Questions
The most common questions about calculating and using cubic feet — answered clearly.
How do I calculate cubic feet?
Multiply length by width by height, with all three measurements in feet. A box 4 ft long, 3 ft wide, and 2 ft high holds 4 × 3 × 2 = 24 cubic feet. If you measured in inches, multiply the three inch values together and divide by 1,728, since there are 1,728 cubic inches in a cubic foot. This calculator does the conversion automatically when you pick the inches unit.
How many cubic inches are in a cubic foot?
There are 1,728 cubic inches in one cubic foot. A foot is 12 inches, so a cubic foot is 12 × 12 × 12 = 1,728 cubic inches. To convert cubic inches to cubic feet, divide by 1,728; to go the other way, multiply by 1,728. This is the conversion that turns a box measured in inches into a volume in cubic feet.
How do I calculate cubic feet from inches?
Measure the length, width, and height in inches, multiply the three numbers together, then divide the result by 1,728. For example, a box 24 inches on every side is 24 × 24 × 24 = 13,824 cubic inches, and 13,824 ÷ 1,728 = 8 cubic feet. Selecting the inches unit in this calculator does the division for you.
How many cubic feet are in a cubic yard?
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 convert cubic yards to cubic feet, multiply by 27. Bulk landscape material is sold by the cubic yard, while bagged material and shipping volume use cubic feet.
How many gallons are in a cubic foot?
One cubic foot holds about 7.48 US gallons. To convert cubic feet to gallons, multiply by 7.48; to convert gallons to cubic feet, divide by 7.48. This conversion matters for tanks, aquariums, and water features — a 10-cubic-foot tank holds roughly 75 gallons.
How do I find the cubic feet of a cylinder?
The volume of a cylinder is π (about 3.14159) times the radius squared, times the height. The radius is half the diameter. For a tank 2 feet across and 4 feet tall, the radius is 1 foot, so the volume is 3.14159 × 1 × 1 × 4 ≈ 12.6 cubic feet. Select the Cylinder shape in this calculator and enter the diameter and height.
What is the cubic feet of a refrigerator?
Most household refrigerators range from about 18 to 28 cubic feet of total capacity, combining the fridge and freezer compartments. Compact and apartment units run 10 to 18 cubic feet. The figure measures interior storage volume, not the appliance's outside dimensions. Manufacturers list it on the spec sheet, but you can also measure the interior and calculate it.
How do I convert cubic feet to cubic meters?
Multiply cubic feet by 0.0283 to get cubic meters. To go the other way, multiply cubic meters by 35.31 to get cubic feet. For example, 100 cubic feet is 100 × 0.0283 = 2.83 cubic meters. Cubic feet is an imperial unit; most of the world measures volume in cubic meters.
How do I calculate cubic feet for shipping?
Measure the length, width, and height of the package in inches, multiply them together, and divide by 1,728 to get cubic feet. Carriers use this volume to work out dimensional weight — a pricing method that charges for the space a shipment occupies when it is light but bulky. Round each dimension up to the next inch, since carriers measure to the outermost point.
How many cubic feet is a standard moving box?
Moving boxes are sized by volume: a small box is about 1.5 cubic feet, a medium box about 3 cubic feet, a large box about 4.5 cubic feet, and an extra-large box about 6 cubic feet. To estimate a whole move, multiply the count of each box size by its cubic feet and add the totals — this calculator's quantity field does that in one step.
What is dimensional weight and how is it related to cubic feet?
Dimensional weight is a shipping charge based on a package's volume rather than its actual weight, used so carriers are paid fairly for light but bulky items. The package's cubic-inch volume is divided by a carrier-specific factor to produce a billable weight. Knowing the cubic feet of a shipment is the first step in estimating whether it will be billed by size or by weight.
How accurate does my measurement need to be?
For most purposes, measuring each dimension to the nearest inch is accurate enough — small errors have a limited effect on the total volume. For shipping, round each dimension up to the next whole inch, since carriers measure to the outermost point and round up. For tanks and precise capacity work, measure carefully and account for wall thickness, which reduces the usable interior volume.
More Tools You'll Love
Cubic feet is one volume unit among several. These companion calculators handle the related measurements your project needs.
Find Any Volume in Cubic Feet
in 30 Seconds
Enter the dimensions of a box, cylinder, or prism — get the volume in cubic feet, cubic inches, cubic yards, cubic meters, gallons, and liters. Feet or inches input. All free.
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