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Instantly convert volume and capacity between liters, gallons, milliliters, cups, cubic meters, and more. Compare your conversion visually, share a permanent link, and print a clean ad-free result. All calculations happen in your browser — your data never leaves your device.
Conversion factors sourced from NIST and SI standard definitions. Results are mathematically exact within floating-point precision.
A US gallon equals approximately 3.785 liters, while a UK (imperial) gallon equals approximately 4.546 liters. The UK gallon is about 20% larger than the US gallon, so always confirm which standard a recipe, fuel rating, or container label is using before converting.
A US cup equals approximately 236.59 milliliters. This converter calculates that automatically when you select cup as your From or To unit, along with conversions to tablespoons, teaspoons, fluid ounces, and metric units.
A fluid ounce measures volume (approximately 29.57 milliliters in the US system), while a regular ounce measures weight. They are not interchangeable unless you also know the density of the substance being measured, which is why this tool only converts between volume units.
Small rounding differences between converters usually come from how many decimal places are displayed or whether US or UK unit definitions are used. This tool uses standard NIST and SI conversion factors and displays results to four decimal places for precision.
Yes. All calculations happen entirely in your browser. No data you enter is ever transmitted to our servers. QuickITTools.com does not collect or store information you enter into this tool.