Cubic Feet Calculator
Enter length, width and height in any unit — feet, inches, yards, meters or centimeters. The calculator converts and multiplies in real time, with no submit button.
How to Calculate Cubic Feet
Cubic feet (ft³) measure the volume of a three-dimensional space. To calculate cubic feet, multiply length by width by height when all dimensions are in feet:
Volume (ft³) = Length (ft) × Width (ft) × Height (ft)
If your measurements are in different units, convert each to feet first, then multiply. The calculator above handles mixed units automatically.
Cubic Feet Formula
Volume = L × W × H
One cubic foot (1 ft³) is the volume that fills a cube measuring 1 foot on every side — equivalent to 1,728 cubic inches (in³), 0.037 cubic yards (yd³), or 28.317 liters (L).
How to Calculate Cubic Feet from Inches
Method 1: Divide each inch measurement by 12 to convert to feet, then multiply.
Method 2: Multiply all three inch measurements together to get cubic inches, then divide by 1,728.
Example: A box measuring 24 in × 18 in × 12 in.
Method 1: 2 ft × 1.5 ft × 1 ft = 3 ft³
Method 2: 24 × 18 × 12 = 5,184 in³ ÷ 1,728 = 3 ft³
How to Calculate Cubic Feet from Meters
Multiply each meter measurement by 3.281 to convert to feet, then multiply the three dimensions together. Alternatively, calculate cubic meters first, then multiply by 35.315.
Example: 2 m × 1.5 m × 0.5 m = 1.5 m³ × 35.315 = 52.97 ft³
How to Calculate Cubic Feet from Yards
Multiply each yard measurement by 3 to convert to feet, then multiply. Or calculate cubic yards first and multiply by 27, because 1 cubic yard equals exactly 27 cubic feet.
Square Feet to Cubic Feet
If you know the area in square feet and need the volume, multiply area by depth:
Volume (ft³) = Area (ft²) × Depth (ft)
This is the most common calculation for landscaping materials: multiply the bed area in square feet by the desired depth (converted to feet) to find how much soil, mulch or gravel to order.
A depth of 3 inches = 0.25 ft. A depth of 6 inches = 0.5 ft. A depth of 12 inches = 1 ft.
→ Use the dedicated Square Feet to Cubic Feet calculator.
Cubic Feet to Cubic Yards
1 cubic yard = 27 cubic feet. To convert, divide cubic feet by 27.
| Cubic Feet | Cubic Yards | Cubic Meters |
|---|---|---|
| 1 | 0.037 | 0.028 |
| 5 | 0.185 | 0.142 |
| 10 | 0.37 | 0.283 |
| 27 | 1 | 0.765 |
| 50 | 1.852 | 1.416 |
| 100 | 3.704 | 2.832 |
| 200 | 7.407 | 5.663 |
| 500 | 18.519 | 14.158 |
Calculating Cubic Feet of Irregular Shapes
Divide the shape into regular sections, calculate the cubic feet of each section, then add the totals together.
Example: An L-shaped room. Split the L into two rectangles. Calculate each rectangle's cubic feet separately, then sum them.
Cubic Feet for Landscaping
Soil and Topsoil
Calculate cubic feet of soil by multiplying the bed area (length × width in feet) by the planting depth (in feet). Topsoil for new lawns is typically applied 2–4 inches deep; raised garden beds need 8–12 inches. Most bagged soil is sold in 0.5, 1 or 2 ft³ bags, so cubic feet is the most useful planning unit. See the soil calculator.
Mulch
Mulch is spread 2–4 inches deep over planting beds. Multiply the bed area in square feet by the depth in feet to get cubic feet. Bagged mulch is commonly sold in 2 ft³ bags, while bulk mulch is sold by the cubic yard (27 ft³). Use the mulch calculator to plan your order.
Gravel
Gravel for driveways and paths is typically 3–6 inches deep. Multiply area × depth (both in feet) to get cubic feet, then multiply by the material density to estimate weight. Suppliers usually quote in cubic yards and tons — try the gravel calculator.
Compost and Raised Beds
For raised beds, fill to within 1–2 inches of the rim. A 4 ft × 8 ft bed at 12 inches deep needs 32 cubic feet of soil/compost mix. Most bagged compost is 1 ft³, making cubic feet the natural ordering unit.
Cubic Feet for Construction
Concrete Slabs and Footings
Concrete is calculated in cubic feet by multiplying length × width × thickness (all in feet). Because ready-mix concrete is delivered by the cubic yard, divide the cubic feet by 27 to find how many yards to order. Add 5–10% extra for waste and over-pour. See the concrete calculator.
Fill Dirt and Excavation
Excavation volume equals length × width × depth. Fill dirt compacts by 10–20% under load, so multiply the excavation cubic feet by 1.15 to estimate how much loose fill to order. Suppliers price fill dirt by the cubic yard. Use the fill dirt calculator.
Cubic Feet for Appliances and Storage
Refrigerators and Freezers
Refrigerator capacity is rated in cubic feet of interior space. Measure the inside cavity width, depth and height in inches, multiply, and divide by 1,728. Standard fridges range from 18 to 26 ft³; compacts are 1.7 to 4.5 ft³. See refrigerator cubic feet.
Storage Units
Common storage unit sizes: 5×5×8 (200 ft³), 5×10×8 (400 ft³), 10×10×8 (800 ft³), 10×20×8 (1,600 ft³). Estimate your load volume to pick the right size — see the storage calculator.
Moving Trucks
Moving trucks list capacity in cubic feet: a 10-ft truck holds about 380 ft³, a 26-ft truck around 1,700 ft³. Measure each large item and sum the volumes for a rough load estimate.
Cubic Feet Conversion Reference
| Cubic Feet | Cubic Yards | Cubic Meters | Cubic Inches | US Gallons | Liters |
|---|---|---|---|---|---|
| 0.5 | 0.0185 | 0.0142 | 864 | 3.74 | 14.16 |
| 1 | 0.037 | 0.0283 | 1,728 | 7.48 | 28.32 |
| 2 | 0.0741 | 0.0566 | 3,456 | 14.96 | 56.63 |
| 5 | 0.1852 | 0.1416 | 8,640 | 37.4 | 141.58 |
| 10 | 0.3704 | 0.2832 | 17,280 | 74.81 | 283.17 |
| 25 | 0.9259 | 0.7079 | 43,200 | 187.01 | 707.92 |
| 50 | 1.8519 | 1.4158 | 86,400 | 374.03 | 1,415.84 |
| 100 | 3.7037 | 2.8317 | 172,800 | 748.05 | 2,831.68 |
Real World Examples
Example 1 — Comparing Two Storage Boxes
Box A measures 24 × 18 × 16 inches. Box B measures 30 × 14 × 14 inches. Which holds more? Box A: 24 × 18 × 16 = 6,912 in³ ÷ 1,728 = 4.0 ft³. Box B: 30 × 14 × 14 = 5,880 in³ ÷ 1,728 = 3.4 ft³. Box A holds about 18% more volume even though Box B looks longer.
Example 2 — Calculating a Car Trunk (L-shaped)
A trunk shape can be split into a main rectangle and a smaller cutout under the rear deck. Rectangle 1: 42 × 36 × 18 in = 27,216 in³. Rectangle 2 (cutout): 18 × 36 × 6 in = 3,888 in³. Total: 31,104 in³ ÷ 1,728 = 18.0 ft³ of cargo space.
Example 3 — Garden Raised Bed Soil Volume
A raised bed 6 ft long × 3 ft wide × 10 in deep. Convert depth: 10 ÷ 12 = 0.833 ft. Volume = 6 × 3 × 0.833 = 15 ft³. That's fifteen 1-ft³ bags or one half-yard bulk delivery.
Example 4 — Concrete Slab for a Shed
A 10 ft × 12 ft shed slab at 4 inches thick. Depth: 4 ÷ 12 = 0.333 ft. Volume = 10 × 12 × 0.333 = 40 ft³. Convert to cubic yards: 40 ÷ 27 = 1.48 yd³. Order 1.5 yd³ to allow for waste.
Accuracy of These Calculations
Every formula on this page uses standard NIST-published conversion factors: 1 cubic foot equals exactly 0.0283168 cubic meters, 1,728 cubic inches, 7.48052 US gallons, and 28.3168 liters. Material density figures for soil, gravel, concrete and mulch reflect typical published industry averages — actual density varies with moisture content and compaction, so treat weight estimates as planning numbers rather than exact totals. For structural, legal or engineering decisions, confirm figures with a licensed contractor or engineer. See the about page for our full methodology.
Frequently Asked Questions
What is a cubic foot?
A cubic foot (ft³) is a unit of volume equal to a cube with sides measuring 1 foot each. One cubic foot holds 1,728 cubic inches, 7.48 US gallons, or 28.32 liters.
How do I calculate cubic feet from inches?
Multiply your length, width and height in inches together to get cubic inches, then divide by 1,728. Example: 24 × 18 × 12 = 5,184 in³ ÷ 1,728 = 3 ft³.
How many cubic feet are in a cubic yard?
27 cubic feet equal 1 cubic yard. To convert cubic feet to cubic yards, divide by 27.
How do I convert square feet to cubic feet?
Multiply square feet by the depth in feet. A 100 sq ft area at 6 inches deep (0.5 ft) = 50 ft³.
What is the volume of a 5 ft × 5 ft × 5 ft cube?
125 cubic feet. Multiply 5 × 5 × 5 = 125 ft³.
How do I calculate cubic feet for a cylinder?
Use the formula: π × radius² × height. Enter the values into our cylinder calculator at /cylinder.
How many cubic feet of soil do I need for a raised garden bed?
Multiply length × width × depth. A 4 ft × 8 ft bed at 12 inches deep (1 ft) needs 32 ft³ of soil.
How do I convert cubic feet to gallons?
Multiply cubic feet by 7.48. One cubic foot holds 7.48 US gallons.
What is the difference between cubic feet and square feet?
Square feet measure area (length × width, a flat surface). Cubic feet measure volume (length × width × height, a three-dimensional space).
How do I calculate cubic feet of concrete?
Multiply length × width × depth of the slab in feet. For a 10 ft × 10 ft slab at 4 inches thick (0.333 ft): 10 × 10 × 0.333 = 33.3 ft³. Divide by 27 to convert to cubic yards for ordering.
How do I measure a refrigerator in cubic feet?
Measure the inside cavity — width, depth, and height in inches. Multiply the three numbers together and divide by 1,728 for cubic feet.
How many cubic feet are in a cubic meter?
1 cubic meter equals 35.315 cubic feet. To convert cubic meters to cubic feet, multiply by 35.315.
How many cubic feet are in a gallon?
1 US gallon equals 0.1337 cubic feet. To convert gallons to cubic feet, divide the gallon figure by 7.48.
How do I calculate cubic feet for shipping or freight?
Measure length × width × height in inches for each package, divide by 1,728 for cubic feet per unit, then multiply by the number of units. Freight carriers use this total plus weight to set the shipping class — see the shipping calculator.
How many cubic feet is a washing machine?
Front-load washers hold 4.0 to 4.5 ft³ of drum capacity. Top-load washers range from 3.5 to 5.5 ft³. Check the interior drum dimensions (diameter and depth in inches) and divide by 1,728 to confirm the exact figure.
What is CBM and how does it relate to cubic feet?
CBM (cubic meter) is the standard volume unit for international freight and ocean shipping. 1 CBM equals 35.315 cubic feet. Multiply a CBM figure by 35.315 to get cubic feet, or use the cubic meters calculator.
How do I calculate cubic feet of a room for insulation or HVAC?
Multiply the room's length × width × height in feet to get cubic feet, then use that figure with your insulation R-value or the BTU calculator to size heating and cooling equipment.