What This Converter Does

Liquid volume gets measured in a wider mix of units than almost anything else — a beverage label in liters, a recipe in cups, a car's fuel tank in gallons. This tool takes a value in one of those units and converts it to another, covering both the metric side (milliliters and liters) and the US customary side (teaspoons through gallons) in a single converter.

How to Use It

Enter a Value and choose a From Unit and To Unit, then click Convert. The eleven supported units are milliliters, liters, cubic meters, US teaspoons, US tablespoons, US fluid ounces, US cups, US pints, US quarts, US gallons, and UK/Imperial gallons — the dropdown lists "Gallon (US)" and "Gallon (UK/Imperial)" as two separate, genuinely different options, not one shared "gallon" unit, since a UK gallon (4.54609 liters) is meaningfully larger than a US gallon (3.78541 liters) — about 20% more.

The Formula

Liters serve as the common base. Milliliters convert by dividing by 1,000; cubic meters convert by multiplying by 1,000 (1 m³ = 1,000 L); the US customary units each have their own liters-per-unit factor: teaspoon × 0.00492892, tablespoon × 0.0147868, fluid ounce × 0.0295735, cup × 0.236588, pint × 0.473176, quart × 0.946353, and US gallon × 3.78541. The UK/Imperial gallon uses its own separate factor, × 4.54609 — the exact value the UK has defined a gallon as since 1985, not a rounded approximation, and not derived from the US gallon's factor at all. A conversion between any two units first turns your input into liters using its source factor, then divides by the target unit's factor, rounded to 5 decimal places.

A Worked Example

2 US gallons converts to 7.57082 liters: 2 × 3.78541 (the gallon's own liters factor) gives that result directly, since gallon-to-liter is already a straight multiplication with liters as the base unit. Going the other way, 3 liters converts to 3.17006 US quarts — 3 ÷ 0.946353 — a case where you divide instead of multiply, because you're converting out of the base unit rather than into it. For cubic meters, 1 m³ converts to 264.17218 US gallons: 1 × 1,000 gives 1,000 liters, then 1,000 ÷ 3.78541 (the gallon's factor) gives the final result — the same two-step process, just with an extra hop through the cubic meter's own 1,000 L factor first.

For the two gallon types specifically: 1 UK/Imperial gallon converts to 1.20095 US gallons — 4.54609 ÷ 3.78541 — confirming the UK gallon is genuinely the larger of the two, not just a rounding difference. Converted to liters directly, 1 UK gallon is exactly 4.54609 L, versus 3.78541 L for 1 US gallon.

How to Convert Volume Manually

Route through liters as the common stepping stone. To convert a US customary unit to liters, multiply by its own factor — 2 gallons × 3.78541 = 7.57082 liters. To go the other way, from liters to a customary unit, divide by that same factor — 3 liters ÷ 0.946353 = 3.17006 quarts. Converting between two non-metric units, like cups to quarts, is easiest done in two hops: convert your starting unit to liters first, then convert that liter figure into your actual target unit, rather than trying to look up or derive a direct cups-to-quarts factor.