Calculate cubic feet for boxes, rooms, cylinders, soil volume, storage space, and material estimates.
Use box mode for rectangular spaces and soil beds. Use cylinder mode for round containers, tanks, posts, and pipes.
box ft³ = length × width × height; cylinder ft³ = π × radius² × heightCubic feet measure three-dimensional volume. For a rectangular box, multiply length, width, and height in feet. For a cylinder, multiply pi by radius squared and height.
| Symbol | Variable | Description |
|---|---|---|
| L, W, H | Box dimensions | Length, width, and height or depth after converting to feet. |
| r | Radius | Half the cylinder diameter, converted to feet. |
Choose box or cylinder
Use box mode for rooms, planters, refrigerators, and storage containers. Use cylinder mode for round shapes.
Select input units
Enter dimensions in feet, inches, yards, centimeters, or meters. The calculator converts them to feet automatically.
Calculate volume
Read cubic feet, cubic yards, cubic inches, and liters in the result panel.
To calculate cubic feet from inches, multiply length, width, and height in inches, then divide by 1,728 because one cubic foot equals 1,728 cubic inches.
| Input | Conversion |
|---|---|
| Formula | ft³ = in³ ÷ 1,728 |
| 1 cubic foot | 1,728 cubic inches |
| 24 × 18 × 12 in box | 3 cubic feet |
For soil, mulch, or gravel, use length × width × depth. Enter bed dimensions in feet, or switch to inches if your depth is measured in inches.
| Material estimate | Result |
|---|---|
| 12 sq ft at 6 in deep | 6 ft³ |
| Cubic feet formula | Square feet × depth in feet |
| Cubic yards estimate | Cubic feet ÷ 27 |
Square feet measure area, so you need a depth or height before you can calculate cubic feet. This is the most common missing step in soil, mulch, insulation, concrete, and storage-volume searches.
| Area and depth | Cubic feet |
|---|---|
| 100 sq ft at 3 in deep | 25 ft³ |
| 100 sq ft at 6 in deep | 50 ft³ |
| 100 sq ft at 12 in deep | 100 ft³ |
For a cylinder, enter radius and height. If you measured diameter, divide it by two before entering the radius.
A refrigerator cubic feet calculator or box cubic feet calculator uses the same rectangular volume method: length × width × height. Measure the usable interior space when you need storage capacity rather than outside dimensions.
Good cubic feet results depend on measuring the usable space, not just the outside dimensions. For boxes and appliances, measure the interior. For soil or concrete, measure the area and average depth. For cylinders, use radius rather than diameter.
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