Cubic Feet Calculator

How to Calculate Cubic Feet

This cubic feet calculator measures the three-dimensional volume of a rectangular space. The formula is simple:

Volume (ft³) = Length (ft) × Width (ft) × Height (ft)

If your dimensions are in other units, convert to feet first — divide inches by 12, multiply meters by 3.28084, multiply yards by 3. This calculator accepts any mix of units per dimension, so you can enter a length in meters, a width in inches, and a height in feet without doing any manual conversion. It also returns the result in cubic yards, cubic meters, liters, and US gallons so you can use whatever unit your project requires.

Step-by-Step Example

1. Measure the length, width, and height of the space or object
2. Select the correct unit for each dimension from the dropdown
3. Enter the values — the calculator converts all three to feet internally
4. Read the volume in cubic feet plus all converted equivalents

Cubic Feet to Cubic Yards Conversion

There are 27 cubic feet in one cubic yard — because one yard = 3 feet, and 3 × 3 × 3 = 27. This conversion is the most common one in construction and landscaping: concrete, mulch, topsoil, gravel, and sand are all sold by the cubic yard. To convert cubic feet to cubic yards, divide by 27. If you need to figure out how many bags or yards of concrete your project requires, the concrete slab calculator handles that end-to-end with bag counts and cost estimates.

Volume Conversion Reference

These are the exact conversion factors the calculator uses for each output unit:

• 1 ft³ = 1,728 in³ (12 × 12 × 12)
• 1 ft³ = 0.037037 yd³ (divide by 27)
• 1 ft³ = 0.028317 m³
• 1 ft³ = 28.317 liters
• 1 ft³ = 7.4805 US gallons

These factors are exact to 5 significant figures. For most practical applications — ordering materials, sizing tanks, calculating shipping — 4 decimal places is more than sufficient precision.

Real-World Applications

Cubic feet calculations come up constantly in everyday projects:

• Shipping and freight — carriers use cubic feet (or the equivalent dimensional weight) to price large, light packages. A standard pallet space is roughly 48 × 40 × 48 inches = 53.3 cubic feet.
• Storage units — a 10×10 unit with 8-foot ceilings is 800 cubic feet. A 5×10 unit is 400 cubic feet. Knowing the cubic footage helps you estimate how much furniture and boxes will fit.
• HVAC and ventilation — room volume in cubic feet is multiplied by the required air changes per hour (ACH) to size exhaust fans and HVAC systems. A typical bedroom at 12×12×9 ft = 1,296 ft³ needs roughly 65–130 CFM of ventilation.
• Landscaping materials — topsoil, mulch, and gravel are sold by the cubic yard. Divide your cubic feet result by 27 to get the yards to order, then add 10% for waste and settling.
• Aquariums and water tanks — multiply cubic feet by 7.4805 to get US gallons. A 4×2×2 ft tank holds 16 cubic feet or about 120 gallons.

Cubic Feet vs. Cubic Meters

The US uses cubic feet for most everyday volume measurements; the rest of the world uses cubic meters. One cubic meter equals 35.315 cubic feet — roughly the volume of a large wardrobe. Shipping containers are sized in cubic meters internationally: a standard 20-foot shipping container has an internal volume of about 33.2 m³ (1,172 ft³). For cylinder-shaped volumes like pipes, tanks, and columns, use the cylinder volume calculator which handles circular cross-sections in the same unit-flexible way.

Tips for Accurate Measurements

• Irregular spaces — for L-shaped rooms, break the space into two rectangles, calculate each separately, and add the results.
• Walls and floors — always measure the interior dimensions, not the exterior. Walls are typically 4.5 inches thick (including drywall on both sides).
• Add a waste factor — for landscaping materials, add 10–15% to the calculated volume to account for settling, uneven ground, and spillage.
• Odd units — if you have a dimension in an unusual unit, convert it to feet or inches first. 1 meter = 3.281 feet; 1 centimeter = 0.0328 feet.