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US gallons to cubic feet (gal to cu ft)

To convert US gallons to cubic feet (gal to cu ft): one US gallon is 0.13368056 cubic feet, so 300 gal is 40.1042 cu ft.

Swap units: cu ft to gal

In cubic feet40.1042 cu ft

Conversion factor Exact by definition: the ratio belongs to the customary units themselves and does not change.
1 US gallon = 0.1336805556 cubic feet
The other way
1 cubic foot = 7.480519481 US gallons
Working
300 x 0.1336805556 = 40.1042
300 gal in every unit
1,135,624 ml 1,135.6 L 230,400 tsp 76,800 tbsp 38,400 fl oz 4,800 cup 2,400 pt 1,200 qt 300 gal 249.8 imp gal 40.104 cu ft 1.4853 cu yd 1.1356 m3
US gallons to cubic feet
galcu ft
10.133681
20.267361
50.668403
101.33681
253.34201
506.68403
10013.3681

How the Unit Converter works

One US gallon is exactly 231/1728 of a cubic foot, which is 0.1336805556. The gallon is defined as 231 cubic inches and a cubic foot is 12 cubed, 1,728 cubic inches.

Worked through: 100 gal x 0.133680556 = 13.3681 cu ft.

Going the other way, one cubic foot is 7.480519481 US gallons.

For mental arithmetic: Divide by 7.5. Or multiply by 0.134.

The direction for sizing something that has to hold water, and the number that matters after it is weight. A 500-gallon tank is 66.8 cubic feet, and water weighs about 8.3 pounds a gallon or 62.4 pounds a cubic foot, so that tank holds over two tons of water. That is why an aquarium, a hot tub or a water bed is a floor-loading question before it is a decorating one: a 300-gallon hot tub full of water and people can put several thousand pounds on a deck sized for furniture.

Precision is worth matching to the input. A measurement given as 1 gal carries one or two significant figures, and reporting its conversion to six implies a precision the original never had.

Unit Converter FAQ

How many cubic feet are in a US gallon?

0.13368056. One US gallon is exactly 231/1728 of a cubic foot, which is 0.1336805556. The gallon is defined as 231 cubic inches and a cubic foot is 12 cubed, 1,728 cubic inches.

What is 300 gal in cubic feet?

40.1042 cu ft. Multiply by 0.13368056: 100 gal x 0.133680556 = 13.3681 cu ft.

How do I convert cubic feet back to US gallons?

Divide by 0.13368056, or equivalently multiply by 7.4805195. One cubic foot is 7.4805195 US gallons. The two factors are reciprocals, so you only need to remember one of them.

Is there a quick way to do this in my head?

Divide by 7.5. Or multiply by 0.134. It is close enough for everyday use.

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