Cubic Feet to Gallons Converter
Convert cubic feet (ft³) to US gallons (gal)
Cubic Foot
Definition: The cubic foot (symbol: ft³ or cu ft) is a unit of volume used in the imperial and US customary measurement systems. One cubic foot equals exactly 7.48052 US gallons, or the volume of a cube with sides of 1 foot (12 inches) each. It equals 1,728 cubic inches.
History/origin: The cubic foot derives from the foot, which has been used as a unit of length since ancient times. The cubic foot became standardized for volume measurements in construction, engineering, and water management. It's particularly useful for measuring large volumes of materials, water, or gas.
Current use: The cubic foot is commonly used in the United States for measuring volumes of water (water tanks, pools, aquariums), natural gas consumption, freight and cargo capacity, HVAC air flow, concrete quantities, and storage spaces. Converting cubic feet to gallons is essential for water tank sizing, pool volume calculations, and understanding utility bills.
Gallon (US)
Definition: The US gallon is a unit of volume used primarily in the United States for measuring liquids. One US gallon equals exactly 231 cubic inches or 0.133681 cubic feet. The gallon is the largest standard liquid measurement in the US customary system.
History/origin: The gallon has ancient origins dating back to Roman times. The US gallon was standardized in 1832 and is based on the wine gallon, defined as exactly 231 cubic inches. The relationship with cubic feet (1 ft³ = 7.48052 gallons) is fundamental to water management and engineering.
Current use: The US gallon is commonly used for measuring gasoline, milk, water, and other liquids in the United States. It's the standard unit for fuel economy (miles per gallon), large beverage containers, and water tank capacities. Converting from cubic feet helps with pool sizing, water storage planning, and utility calculations.
Cubic Feet to Gallons Conversion Table
| Cubic Feet [ft³] | Gallons [gal] |
|---|---|
| 0.1 ft³ | 0.748 gal |
| 0.5 ft³ | 3.740 gal |
| 1 ft³ | 7.481 gal |
| 2 ft³ | 14.961 gal |
| 5 ft³ | 37.403 gal |
| 10 ft³ | 74.805 gal |
| 25 ft³ | 187.013 gal |
| 50 ft³ | 374.026 gal |
| 100 ft³ | 748.052 gal |
| 1000 ft³ | 7,480.520 gal |
How to Convert Cubic Feet to Gallons
Formula:
1 ft³ = 7.48052 gal (US)
1 gal = 0.133681 ft³
gal = ft³ × 7.48052
Quick Approximation:
Multiply ft³ by 7.5 for a rough estimate in gallons
Or think: 1 cubic foot ≈ 7.5 gallons
Common Conversions:
0.1 ft³ = 0.748 gal
1 ft³ = 7.481 gal
2 ft³ = 14.961 gal
5 ft³ = 37.403 gal
10 ft³ = 74.805 gal
100 ft³ = 748.052 gal
Useful Relationships:
1 cubic foot = 7.481 gal = 28.317 L = 1,728 in³
1 gallon = 0.134 ft³ = 231 in³ = 3.785 L
1 cubic yard = 27 ft³ = 201.974 gal
Examples:
Convert 1 cubic foot to gallons:
1 ft³ × 7.481 = 7.481 gal
This is approximately 7.5 gallons
Convert 10 cubic feet to gallons:
10 ft³ × 7.481 = 74.805 gal
This is approximately 75 gallons
Convert 50 cubic feet to gallons:
50 ft³ × 7.481 = 374.026 gal
This is approximately 374 gallons (a medium water tank)
Convert 100 cubic feet to gallons:
100 ft³ × 7.481 = 748.052 gal
This is approximately 748 gallons (a large aquarium or small pool)
Practical Applications:
Water Tank Sizing: A 4' × 4' × 5' tank = 80 ft³ = ~600 gallons
Pool Volume: 15' × 30' × 5' avg depth = 2,250 ft³ = ~16,830 gallons
Aquarium: 2' × 1' × 1.5' = 3 ft³ = ~22.5 gallons