Rectangular Volume
Volume in cubic feet for a room, box, or slab. cuft = length(ft) × width(ft) × height(ft). Each dimension is converted to feet before multiplying.
Math
About Cubic Feet Calculator
Calculate cubic feet from rooms, boxes, square feet plus depth, cylinders, logs, and concrete slabs.
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About this calculator
What this does
Calculates the volume of a space or object in cubic feet using four shape modes: rectangular room or box, square footage plus depth, cylinder or round log, and concrete slab. Converts the result to cubic meters, liters, and US gallons so you can compare across unit systems without additional math.
Who it is for
Homeowners measuring room or fridge space, contractors estimating concrete or material volume, movers calculating truck capacity, woodworkers sizing logs, and anyone who needs a quick volume check in cubic feet across imperial and metric units.
How it works
Select a shape mode and a linear unit (ft, in, m, cm). Enter the required dimensions for that mode — length, width, and height for a room; area and depth for square footage; diameter and length for a cylinder; or length, width, and depth for a slab. The calculator converts every input to feet, applies the geometric volume formula, and displays the result in four unit views.
Limitations
Assumes perfectly rectangular, cylindrical, or slab geometries. Does not account for irregular shapes, tapered columns, curved walls, rounded corners, sloping floors, void spaces, or material compression. Results are exact for the given dimensions but should be treated as estimates for real-world objects.
Formula
Square Feet Plus Depth
Volume from an area measurement and a depth. cuft = area(sqft) × depth(ft). Depth is converted to feet from the chosen linear unit.
Cylinder Volume
Volume for a round log, pipe, or cylinder. cuft = π × (diameter(ft) / 2)² × length(ft). The calculator halves the diameter to get the radius, squares it, multiplies by π, then by the length.
Unit Conversion
After computing cubic feet, the result is converted to cubic meters (× 0.0283168), liters (× 28.3168), and US gallons (× 7.48052) for cross-unit comparison.
How it works
Step 1
Select a shape mode
Choose between Room / Box, Square Feet + Depth, Cylinder / Round Wood, or Concrete Slab to set the input fields for your use case.
Step 2
Choose a linear unit
Pick ft, in, m, or cm. For Square Feet + Depth mode you also pick the area unit (sq ft or sq m). All inputs are converted to feet internally.
Step 3
Enter the dimensions
Fill in the required fields for your mode — length, width, and height for room mode; area and depth for depth mode; diameter and length for cylinder mode; or length, width, and depth for slab mode.
Step 4
Read the volume results
The calculator displays the volume in cubic feet, cubic meters, liters, and US gallons at once. The formula used and a mode-specific note are shown below the results.
Step 5
Check the worked formula
The formula bar shows the exact expression used for the current mode, and the note column explains the conversion or geometric rule applied.
Reference ranges
Small appliance or cooler
A mini-fridge or cooler is typically 3–6 ft³. A standard dorm fridge falls around 4.5 ft³. Anything below 2 ft³ is a compact cooler or small ice chest.
Standard refrigerator
Full-size refrigerators range from 18 to 28 ft³. French-door models often sit at 22–26 ft³, while side-by-side units are typically 20–25 ft³.
Concrete slab (4 in thick)
A 10×10 ft slab at 4 in deep is roughly 33 ft³, which equals about 1.2 cubic yards of concrete. A standard parking space (9×18 ft) at 4 in is about 54 ft³.
Round log or tree
A log 12 in diameter and 8 ft long has about 6.3 ft³ of volume. A 24 in diameter log of the same length holds about 25 ft³. Larger timber specimens can exceed 50 ft³.