Volume & measurement

Liquid Volume Converter

Convert gallons, liters, cups, ounces, milliliters, and cubic units before you fill a tank, adjust a recipe, or estimate water weight.

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Convert liquid volume

Use the right unit family

Recipes, product labels, tanks, aquariums, and pools may use different systems. This page keeps common U.S. liquid units and metric units together so the result is easy to check before you pour, buy, fill, or estimate weight.

For water weight, convert the volume first, then use the water weight calculator for pounds or kilograms.

Common liquid-volume conversions

ConversionApproximate resultTypical use
1 U.S. gallon3.785 litersWater, fuel, tanks, pools
1 liter33.814 U.S. fluid ouncesBottles and recipes
1 U.S. cup236.588 millilitersCooking and nutrition labels
1 U.S. tablespoon14.787 millilitersSmall kitchen measurements

Before using the result

Kitchen estimates, aquarium setup, and home projects can tolerate rounding. Medication, laboratory mixing, industrial chemicals, and safety-critical measurements should follow verified instructions from the product, clinician, lab, or supplier.

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