The gallon calculator is a converter that helps you convert gallons to cups, liters, cubic feet and inches, quarts, ounces, and even raindrops! Just input one of the values, and the rest will fill in automatically! It can convert both US and UK gallons. Our calculator can also convert gallons of water to pounds and kilograms.

You need to know how many gallons of water your aquarium or pool can hold? Check out these calculators:

What is a gallon?

A gallon is a unit of volume. It's bigger than a pint, liter, and fluid ounce, but smaller than cubic feet and a US barrel.

A comparison of 1 cup, 1 liter, and 1 gallon

Our calculator has four unit options correlated to gallons:

  • UK gallons
  • US gallons
  • US dry gallons
  • 1k US gallons

The UK gallon is bigger than the US gallon:

1 UK gallon = 1.201 US gallon, whereas 1 US gallon = 0.8317 UK gallon.

1 gallon is equal to 4 quarts, 8 pints, or 16 cups – so exactly the daily water intake for an average male adult.

In the next few paragraphs, you will find values of 1 gallon converted into different volume units.

Convert liters to gallons – metric units

1 US gallon1 UK gallon
milliliter [ml]37854546
centiliter [cl]378.5454.6
liter [l]3.7854.546
hectoliter [hl]0.037850.04546
cubic centimeters [cm3]3785.44546
cubic decimeters [dm3]3.78544.546
cubic meters [m3]0.00378540.004546
cubic kilometers [km3]3.7854·10-124.546·10-12

Convert cubic feet to gallons & convert cubic inches to gallons

1 US gallon1 UK gallon
cubic inches [cu in]231277.4
cubic feet [cu ft]0.133680.16054
cubic yards [cu yd]0.0049510.005946
cubic miles [cu mi]9.08·10-131.091·10-12

Convert quarts to gallons

1 US gallon1 UK gallon
US quarts [US qt]44.804
UK quarts [UK qt]3.3314
US pints [US pt]89.608
UK pints [UK pt]6.6618
US barrels0.0317460.038125

Convert ounces to gallons

1 US gallon1 UK gallon
US fluid ounces [US fl oz]128153.72
UK fluid ounces [UK fl oz]133.23160

Convert gallons to cups

1 US gallon1 UK gallon
US customary cups1619.215
tablespoons (15 ml) [tbsp]252.36303.1
teaspoons (5 ml) [tsp]757.1909.2

Water – gallons to kilograms and pounds

A well-known property of water is that 1 liter weighs approximately 1 kilogram. This is due to its density – the ratio of mass to volume. The density of water changes with temperature. Our gallon calculator has a default value for the density of water at 20 °C (68 °F).

Below, you can see how much 1 US and UK gallons weigh at three different temperatures:

1 US gallon1 UK gallon
4 °C / 39.2 °F3.7856 kg / 8.346 lb4.546 kg / 10.023 lb
21 °C / 69.8 °F3.778 kg / 8.33 lb4.538 kg / 10.004 lb
30 °C / 86 °F3.769 kg / 8.31 lb4.527 kg / 9.98 lb

As you see, the higher the temperature, the lighter water is. To learn more about water density, go to our water density calculator!

How to use the gallon calculator?

First, choose one of the two calculator's modes:

  1. Volume converter – input a value next to any unit, and all the other ones will fill in in a blink of an eye!
  2. Water – volume to weight: Input one of the two: volume or weight, and get the missing value. You can change water density according to your need.

Before you go, take a look at this universal conversion calculator that can convert temperature, length, area, volume, and weight! It can also explain SI unit prefixes!

FAQ

How to calculate gallons in a pool?

To calculate how many gallons your pool will hold, find its volume and convert it to gallons. For example, if your pool volume is in cubic inches, divide the volume by 231. If your pool volume is in cubic feet, multiply the volume by 7.48.

How to convert cubic inches to gallons?

To convert cubic inches to gallons (US), divide the number of cubic inches by 231:

number of US gallons = number of cubic inches / 231

To convert cubic inches to UK gallons, divide the number of cubic inches by 277.4:

number of UK gallons = number of cubic inches / 277.4

How to convert cubic feet to gallons?

To convert cubic feet to US gallons, multiply the number of cubic feet by 7.48:

number of US gallons = number of cubic inches × 7.48.

1 US gallon is equal to 0.13368 cubic feet, and 1 cubic foot is equal to 7.48 US gallons.

To convert cubic feet to UK gallons, multiply the number of cubic feet by 6.229:

number of UK gallons = number of cubic feet × 6.229.

1 UK gallon is equal to 0.16054 cubic feet, and 1 cubic foot is equal to 6.229 UK gallons.

How to convert quarts to gallons?

1 gallon is equal to 4 quarts. To convert quarts to gallons, divide the number of quarts by 4:

number of gallons = number of quarts / 4

How to convert gallons into cups?

To convert gallons to cups, multiply the number of gallons by 16:

number of cups = number of gallons × 16

1 gallon is equal to 4 quarts, 8 pints, 16 cups, or 128 fluid ounces.

Julia Żuławińska
Volume converter
Input any variable:
US gal
liters
cu ft
cu in
US qt
US pt
US fl oz
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