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Gallon to Cubic foot Converter

Enter the value that you want to convert gallon (gal) to cubic foot (ft³) or cubic foot to gallon.Also written as GAL to FT³ conversion.

1 gallon = 0.1605437 cubic foot

Formula: cubic foot = gallon value × 0.1605437

GAL to FT³gallon to cubic foot

gal
1.60544ft³

10 gallon = 1.60544 cubic foot

Popular Volume Converters:

Gallon vs Cubic foot

The Gallon Explained

Gallon (gal) is a unit of volume measurement. 1 gallon is equal to 0.1605437 cubic foot.

What is Cubic foot?

Cubic foot (ft³) is a unit of volume measurement. 1 cubic foot is equal to 6.2288355 gallon.

Volume Measurement Systems

Volume units are particularly confusing because the US and UK gallons differ (US gallon = 3.785 L, UK gallon = 4.546 L), as do their pints, cups, and fluid ounces. Cooking, fuel economy, beverage production, and pharmaceutical compounding all require precise volume conversions. Laboratory work uses milliliters and liters while US recipes specify cups, tablespoons, and fluid ounces.

gallon to cubic foot metric conversion table

0.01 gal=0.00161 ft³
0.1 gal=0.01605 ft³
1 gal=0.16054 ft³
2 gal=0.32109 ft³
3 gal=0.48163 ft³
4 gal=0.64217 ft³
5 gal=0.80272 ft³
6 gal=0.96326 ft³
7 gal=1.12381 ft³
8 gal=1.28435 ft³
9 gal=1.44489 ft³
10 gal=1.60544 ft³
11 gal=1.76598 ft³
12 gal=1.92652 ft³
13 gal=2.08707 ft³
14 gal=2.24761 ft³
15 gal=2.40815 ft³
16 gal=2.56870 ft³
17 gal=2.72924 ft³
18 gal=2.88979 ft³
19 gal=3.05033 ft³
20 gal=3.21087 ft³
30 gal=4.81631 ft³
40 gal=6.42175 ft³
50 gal=8.02718 ft³
60 gal=9.63262 ft³
70 gal=11.23806 ft³
80 gal=12.84349 ft³
90 gal=14.44893 ft³
100 gal=16.05437 ft³
200 gal=32.10873 ft³
300 gal=48.16310 ft³
400 gal=64.21746 ft³
500 gal=80.27183 ft³
600 gal=96.32619 ft³
700 gal=112.38056 ft³
800 gal=128.43492 ft³
900 gal=144.48929 ft³
1000 gal=160.54365 ft³

How to Convert GAL to FT³ (Gallon to Cubic foot)?

We can convert gallon to cubic foot by using an example.

Example:

Convert 20 Gallon to Cubic foot?

We know 1 Gallon = 0.1605437 cubic foot; 1 Cubic foot = 6.2288355 gallon.

20 gallon = ___ft³

20 × 0.1605437 = 3.21087 ft³ (we know 1 gallon = 0.1605437 cubic foot)

Answer:

20 gallon = 3.21087 cubic foot

How to Convert Gallons to Cubic Feet

When you need to express liquid volumes in spatial terms — such as figuring out how much space a quantity of water occupies in a tank or pipe — you convert gallons to cubic feet. One US gallon occupies 0.133681 cubic feet of space. This conversion bridges the gap between liquid measurement and spatial/dimensional measurement.

  1. Start with the volume in US gallons.
  2. Multiply by 0.133681 to get cubic feet.
  3. Alternatively, divide gallons by 7.48052.
  4. Example: 100 gallons × 0.133681 = 13.37 ft³.
💡 Tip: Shortcut: divide gallons by 7.5 for a quick estimate. The result is within 0.3% of the exact value — accurate enough for most tank sizing and storage calculations.

Gallons to Cubic Feet Quick Chart

Converting common gallon quantities to cubic feet for tank and pipe sizing:

GallonCubic foot
1 gallon0.134 ft³
5 gallons0.668 ft³
40 gallons5.347 ft³
55 gallons7.353 ft³
100 gallons13.368 ft³
300 gallons40.104 ft³
1,000 gallons133.681 ft³
10,000 gallons1,336.81 ft³

Solved Examples: Gallons → Cubic Feet

Question 1: A water heater holds 50 gallons. What is its internal volume in cubic feet?

Solution:

Cubic feet = gallons × 0.133681

= 50 × 0.133681

= 6.684 ft³

Answer: A 50-gallon water heater has an internal volume of about 6.68 cubic feet.

Question 2: You need to store 2,000 gallons of rainwater. What tank volume in cubic feet is required?

Solution:

Cubic feet = 2,000 × 0.133681

= 267.36 ft³

Answer: You need a tank with at least 267.4 cubic feet of internal volume.

Question 3: A pipe can hold 12 gallons per linear foot. Express this capacity in cubic feet per foot.

Solution:

Cubic feet per foot = 12 × 0.133681

= 1.604 ft³ per foot of pipe

Answer: The pipe holds 1.604 cubic feet of water per linear foot.

Practice Questions

Try solving these on your own to test your understanding:

  1. Convert 75 gallons to cubic feet. (Answer: 10.03 ft³)
  2. A 330-gallon tote — how many cubic feet? (Answer: 44.11 ft³)
  3. How many gallons fit in 20 cubic feet? (Answer: 149.61 gallons)
  4. A fuel tank is 8 ft³. How many gallons? (Answer: 59.84 gallons)
  5. Convert 5,000 gallons to cubic feet. (Answer: 668.4 ft³)

Pipe and Tank Sizing

Engineers size water storage tanks in cubic feet because dimensions (length × width × height) naturally produce cubic feet. Converting the required gallon capacity to cubic feet first lets you determine physical dimensions. For a cylindrical tank: Volume (ft³) = π × r² × h. Then verify gallons = ft³ × 7.48 meets your needs. Always add 10-15% overhead for expansion and incomplete filling.

Propane and Fuel Tanks

Residential propane tanks are sold by gallon capacity (120, 250, 500, 1000 gallon) but must fit in specific physical spaces. Converting to cubic feet helps during site planning: a 500-gallon propane tank occupies about 66.84 ft³ internally. The external dimensions are larger due to tank wall thickness, supports, and safety clearances required by code.

Key Takeaways

  • 1 US gallon = 0.133681 cubic feet.
  • Divide gallons by 7.48 (or multiply by 0.1337) to get cubic feet.
  • A 55-gallon drum takes up about 7.35 cubic feet.
  • Use this conversion for tank sizing: gallons needed ÷ 7.48 = required ft³.
  • Always add 10-15% to calculated tank volumes for safety margin.

Gallon to Cubic foot Conversion Formula

cubic foot = gallon × 0.1605437

1 gallon = 0.1605437 cubic foot

1 cubic foot = 6.2288355 gallon

Reverse: gallon = cubic foot × 6.2288355

Frequently Asked Questions

How many cubic foot are in 1 gallon?

There are 0.1605437 cubic foot in 1 gallon. To convert gallon to cubic foot, multiply the value by 0.1605437.

How do I convert gallon to cubic foot?

Multiply your gallon value by 0.1605437 to get the equivalent in cubic foot. For example, 5 gallon = 5 × 0.1605437 = 0.80272 cubic foot.

How do I convert cubic foot to gallon?

Multiply your cubic foot value by 6.2288355 to get the equivalent in gallon. Alternatively, divide by 0.1605437.

What is 10 gallon in cubic foot?

10 gallon is equal to 1.60544 cubic foot.

What is 100 gallon in cubic foot?

100 gallon is equal to 16.05437 cubic foot.