Cubic Feet Calculator
Instantly calculate the volume of any box, room, or container in cubic feet. Enter your dimensions in feet, inches, yards, meters, or centimeters and get an accurate result with automatic unit conversion.
By Krishna D, Volume Measurement Specialist · Last updated June 30, 2026
What Is Cubic Feet?
Cubic feet (ft³, or "cu ft") is a unit of volume in the US customary and imperial measurement systems. It represents the amount of three-dimensional space occupied by a cube measuring exactly one foot on each side — one foot long, one foot wide, and one foot tall. Cubic feet is the standard volume unit used throughout the United States for everything from refrigerator and freezer capacity to moving truck space, storage unit sizing, soil and mulch quantities, concrete pours, and air conditioning calculations.
Unlike square footage, which only measures a flat, two-dimensional surface, cubic footage accounts for depth as well, giving you the true three-dimensional capacity of a space or object. Whenever you need to know how much "stuff" can fit inside a box, room, container, or vehicle, cubic feet is almost always the unit you are looking for.
Quick definition: 1 cubic foot = the volume of a cube with sides of 1 foot (12 inches) each, equal to 1,728 cubic inches or roughly 28.32 liters.
The Cubic Feet Formula
Calculating cubic feet is straightforward once you have three measurements: length, width, and height. All three must be in the same unit before you multiply them.
If your measurements are in another unit — inches, yards, meters, or centimeters — our calculator above converts them to feet automatically before performing the multiplication, so you never have to do the conversion math by hand.
Step-by-Step: How to Calculate Cubic Feet
- Measure the length of the object or space, in a consistent unit (feet, inches, yards, meters, or centimeters).
- Measure the width using the same unit as the length.
- Measure the height using the same unit as the other two dimensions.
- Select your measurement unit in the calculator above so the tool knows how to convert your numbers.
- Click "Calculate Volume" to instantly see your result in cubic feet, along with automatic conversions to cubic inches, cubic yards, cubic meters, and liters.
Worked Examples
Example 1 — Measuring in Feet
A moving box measures 3 ft long, 2 ft wide, and 2 ft tall.
Volume = 3 × 2 × 2 = 12 cubic feet
Example 2 — Measuring in Inches
A storage container measures 36 in long, 24 in wide, and 18 in tall.
Volume = (36 × 24 × 18) ÷ 1,728 = 15,552 ÷ 1,728 = 9 cubic feet
Example 3 — Measuring in Meters
A small room measures 4 m long, 3 m wide, and 2.5 m tall.
Volume = 4 × 3 × 2.5 = 30 m³ → 30 × 35.3147 = ≈1,059.44 cubic feet
Cubic Feet Conversion Table
| From | To Cubic Feet | Multiply By |
|---|---|---|
| Cubic Inches | Cubic Feet | ÷ 1,728 |
| Cubic Yards | Cubic Feet | × 27 |
| Cubic Meters | Cubic Feet | × 35.3147 |
| Cubic Centimeters | Cubic Feet | ÷ 28,316.8 |
| Liters | Cubic Feet | × 0.0353147 |
| US Gallons | Cubic Feet | ÷ 7.48052 |
Quick Reference: Cubic Feet for Common Box Sizes
| Box Size (L × W × H) | Volume |
|---|---|
| 12 in × 12 in × 12 in | 1.00 ft³ |
| 18 in × 18 in × 16 in | 3.00 ft³ |
| 24 in × 18 in × 18 in | 4.50 ft³ |
| 10 ft × 10 ft × 8 ft (storage unit) | 800.00 ft³ |
| 20 ft × 8 ft × 8.5 ft (shipping container) | 1,360.00 ft³ |
Applications of Cubic Feet Calculations
Cubic feet calculations show up across dozens of practical, everyday scenarios. Below are the most common applications where knowing your volume accurately saves time, money, and frustration.
- Storage: Sizing a self-storage unit correctly so your belongings fit without paying for unused space.
- Construction: Estimating concrete, gravel, sand, or soil needed for a foundation or landscaping project.
- Shipping: Calculating dimensional (volumetric) weight for freight and parcel carriers.
- Moving: Determining how many cubic feet of truck or trailer space your household items will require.
- Aquariums: Confirming tank volume before calculating water weight and filtration needs.
- Pools: Estimating water volume for chemical dosing and fill times.
- Concrete: Converting cubic feet to cubic yards for ready-mix concrete orders.
- Wood: Calculating lumber or firewood volume for pricing and storage planning.
- Furniture: Checking whether large furniture will fit through doorways or into rooms.
- Containers: Comparing the capacity of bins, totes, and shipping containers.
Benefits of Using This Cubic Feet Calculator
While the formula itself is simple, manually converting between feet, inches, yards, meters, and centimeters introduces a lot of room for error. This calculator removes that friction entirely.
- Speed: Get a result in seconds instead of doing manual unit conversion math.
- Accuracy: Built-in conversion constants eliminate rounding mistakes common with manual calculations.
- Flexibility: Works with five different input units, so you never have to convert your measurements beforehand.
- Multi-unit output: See your result in cubic inches, cubic yards, cubic meters, and liters all at once.
- No installation: Runs entirely in your browser on any device, with nothing to download.
Common mistake: Mixing units within the same calculation — for example, entering length in feet but height in inches — is the single most frequent source of error. Always convert all three measurements to the same unit first, or use the unit selector to keep them consistent.
Common Mistakes to Avoid
- Mixing measurement units. Always use the same unit for length, width, and height before calculating.
- Confusing area with volume. Square footage only accounts for two dimensions; cubic footage requires all three.
- Forgetting interior vs. exterior dimensions. For storage units or containers, use interior usable dimensions, not the outer shell measurements.
- Rounding too early. Round only your final answer, not your individual measurements, to avoid compounding small errors.
- Ignoring irregular shapes. This formula applies to rectangular volumes only — break irregular spaces into smaller rectangular sections first.
Helpful Tips for Accurate Measurements
- Use a tape measure rather than estimating by eye, especially for construction or shipping calculations.
- Measure twice and record each dimension before entering it into the calculator.
- For irregular rooms, divide the space into rectangular sections, calculate each separately, and add the totals together.
- When estimating concrete or soil, add a 5–10% buffer to your calculated volume to account for settling and spillage.
- Save or screenshot your result using the Copy Result button so you can reference it later without recalculating.
Frequently Asked Questions
A cubic foot is a unit of volume equal to a cube measuring one foot on every side (1 ft × 1 ft × 1 ft). It is part of the imperial and US customary measurement systems and is commonly abbreviated as ft³ or cu ft.
Multiply length × width × height in inches, then divide the result by 1,728 (since there are 1,728 cubic inches in one cubic foot). Our calculator does this automatically when you select 'Inches' as your unit.
There are 27 cubic feet in one cubic yard, since a yard is 3 feet and 3 × 3 × 3 = 27.
Multiply your cubic feet value by 7.48052 to get US gallons. For liters, multiply by 28.3168.
CFT stands for Cubic Feet, a measurement frequently used to calculate shipping volume, freight charges, and container capacity.
This calculator is designed for rectangular or box-shaped volumes. For irregular shapes, break the object into rectangular sections and calculate each separately, then add the results together.
Yes, the formula used (Length × Width × Height) is the same standard formula used in construction takeoffs for concrete, soil, gravel, and similar materials. Always double-check your measurements on site.
One cubic meter equals approximately 35.3147 cubic feet.
Measure the room's length, width, and ceiling height in feet, then multiply the three numbers together to get the room's volume in cubic feet.
Square feet measures a two-dimensional area (length × width), while cubic feet measures three-dimensional volume (length × width × height).
A standard medium moving box is roughly 3 cubic feet, while a large box is typically around 4.5 cubic feet, though sizes vary by manufacturer.
Multiply the unit's interior length, width, and height in feet. A typical 10×10×8 ft storage unit holds about 800 cubic feet.
For cylindrical volume, use π × radius² × height instead of the rectangular formula. This calculator is built specifically for rectangular volumes.
Results are calculated using precise international conversion constants and displayed to four decimal places for maximum accuracy.
Yes, select 'Centimeters' from the unit dropdown and enter your length, width, and height directly in centimeters.
One liter equals approximately 0.0353147 cubic feet.
Make sure all three fields (length, width, height) contain a positive number greater than zero. The calculator will highlight any empty or invalid field.
Yes, after calculating, use the Copy Result button to copy the value to your clipboard, or the Share button to send it via your device's native share options.
No. This calculator runs entirely in your browser — there is nothing to download or install.
Yes, the Cubic Feet Calculator is free to use for personal, educational, and commercial purposes.
Conclusion
Whether you're packing for a move, ordering concrete for a patio, sizing a storage unit, or calculating shipping costs, knowing how to find cubic feet accurately is an essential, practical skill. This calculator takes the standard formula — Length × Width × Height — and adds automatic unit conversion, instant results, and multi-unit output so you can spend less time doing math and more time getting your project done. Bookmark this page and come back any time you need a quick, reliable volume calculation.