A cubic feet calculator converts between cubic feet (ft³) and 30+ volume units including gallons, liters, cubic meters, and cubic yards. Also calculates volume from foot dimensions.
A cubic foot (ft³) is the volume of a cube with 1-foot sides = 12 × 12 × 12 = 1,728 cubic inches. It is the standard volume unit in US construction, HVAC, shipping, and real estate.
1 cubic foot = 7.481 US gallons = 28.317 liters = 0.02832 cubic meters.
V (ft³) = Length (ft) × Width (ft) × Height (ft).
If measurements are in inches: multiply L × W × H in inches, then divide by 1,728.
Example: A room 12 ft × 10 ft × 8 ft = 960 ft³ = 27.18 m³ = 7,182 gal = 27,185 L.
= 7.481 US gal = 28.317 L = 1,728 in³ = 0.02832 m³.
18 ft³ = 134.66 US gal = 509.7 L = 31,104 in³.
= 960 ft³ = 27,185 L. Used for AC sizing (~400 ft²/ton).
= 27 ft³ = 201.97 US gal = 764.55 L.
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Answers to common questions about the cubic feet calculator.
1 cubic foot = 7.481 US gallons = 6.229 Imperial gallons. Multiply ft³ by 7.481 to get US gallons.
Multiply by 0.02832. 1 ft³ = 0.02832 m³. 1 m³ = 35.314 ft³.
27 cubic feet = 1 cubic yard (3 × 3 × 3 = 27). Divide ft³ by 27 to get yd³.
V = L × W × H (all in feet). HVAC sizing: approximately 1 ton of cooling per 400-600 sq ft floor area, or about 12,000 BTU per 400 sq ft.
CFM measures airflow rate — how many cubic feet of air move past a point per minute. HVAC fans, bathroom vents, and dryer exhausts are rated in CFM. A bathroom fan should be 50-110 CFM.