π§ͺ Volume Converter
Convert between gallons, liters, cups, pints, quarts, fl oz, and ml, live as you type.
Converted Volume
How to Use This Converter
Type an amount, choose the unit it is in and the unit you want, and the result updates the instant you type. Every unit lives in both US customary and metric so you never have to guess.
Enter the amount in the Amount box, for example 2 or 16.5.
Pick the From unit: gallons, quarts, pints, cups, fluid ounces, liters, or milliliters.
Pick the To unit. The converted value appears immediately at the top of the results card.
Scan the all-unit table under the result to see the same amount in every other unit at a glance.
Exact Conversion Factors
The US liquid gallon is defined as exactly 231 cubic inches, which works out to 3.785411784 liters, so gallon conversions are exact. Everything smaller cascades from there: a quart is a quarter gallon, a pint is half a quart, a cup is half a pint, and a fluid ounce is one eighth of a cup, all exactly. For quick mental math, 1 gallon β 3.79 liters, 1 liter β 0.264 gallons, 1 quart β 0.95 liters, 1 cup β 237 ml, and 1 fl oz β 30 ml get you within a percent.
Worked Example
You bought 5 gallons of paint and the label also asks for liters. 5 x 3.785411784 = 18.9271 liters. A recipe calls for 4 cups of stock and your measuring jug reads milliliters: 4 x 236.5882365 = 946.353 ml, just under a liter. And a 20 fl oz water bottle in milliliters: 20 x 29.5735295625 = 591.471 ml, the standard bottle size you see on shelves. Run each through the converter and compare with the all-unit table.
Where This Comes Up
Cooking is the number one use: American recipes speak in cups, pints, and quarts while the rest of the world uses milliliters and liters, and converting correctly is the difference between soup and stew. Beverage service leans on the same units: gallons for punch and cold brew, quarts for iced tea, pints for beer. Fuel math flips between gallons and liters whenever you compare US mileage with European car specs. And anyone who works with aquariums, pools, or garden watering systems juggles gallons and liters constantly when dosing treatments or estimating fill times.
Frequently Asked Questions
How many liters are in a gallon?
1 US gallon equals 3.78541 liters. The imperial gallon used in the UK is larger at 4.54609 liters, so make sure you know which gallon a recipe or spec means. US product labels and car specs always use the US gallon.
How many cups are in a gallon?
16 US cups in 1 US gallon. Breaking it down: 1 gallon = 4 quarts = 8 pints = 16 cups = 128 fluid ounces. If a punch recipe serves 16 cups, one gallon covers it.
How many ml are in a fluid ounce?
1 US fluid ounce equals 29.5735 ml. That makes 8 fluid ounces (1 cup) equal 236.588 ml. Medicine cups and shot glasses (1.5 fl oz = 44.36 ml) are the easiest everyday references.
Is a US cup the same as a metric cup?
No, and the gap matters in baking. A US customary cup is 236.588 ml, while the metric cup used in Australia and many international recipes is 250 ml, about 5.7 percent more. If a recipe just says "cups" and comes from Australia, use 250 ml per cup.
How do I convert quarts to liters?
Multiply quarts by 0.946353. 1 quart is just under a liter: 1 liter equals 1.05669 quarts. Motor oil sold in quart bottles and large soda bottles (2 liters = 2.113 quarts) are the common everyday encounters.