TontonTools

Volume Converter

Convert liters, milliliters, gallons, cups, pints and fluid ounces instantly.

100% Free No signup Privacy-friendly Unit Converters
Updated Sep 2026

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How to use Volume Converter

  1. Type the amount in the “From” field — for example 750 for a 750 mL bottle.
  2. Choose your starting unit in the first dropdown (Milliliter, US cup, US gallon…).
  3. Choose the target unit in the second dropdown — the result appears instantly as you type.
  4. Hit the swap button to flip direction, e.g. from gallons → liters to liters → gallons.

What is Volume Converter?

A volume converter changes capacity measurements between units — liters to gallons, milliliters to fluid ounces, cups to milliliters. Metric volume is simple: 1,000 mL to the liter, 1,000 L to the cubic meter. The US customary side is a chain of doublings: 8 fluid ounces to a cup, 2 cups to a pint, 2 pints to a quart, 4 quarts to a gallon.

The bridge is the US gallon, defined as exactly 3.785411784 liters. Watch out for the imperial (UK) gallon, which is a different, larger unit (4.546 L) — this tool uses US measures throughout, which is what recipes, fuel prices and product labels from the US mean.

About the Volume Converter

This converter covers eight units — milliliter, liter, cubic meter, US fluid ounce, US cup, US pint, US quart and US gallon — with instant conversion between any pair as you type.

It earns its keep in the kitchen and at the pump: a recipe calling for 2 cups of stock is 473 mL, a 16.9 fl oz water bottle is 500 mL (that is why the odd number exists), and fuel priced per gallon converts to per-liter by dividing by 3.785. It also handles bigger jobs like converting a 0.5 m³ water tank to liters (500 L) or gallons (132 gal).

All conversions use the exact US definitions and run entirely in your browser — instant, private and free.

Frequently Asked Questions

One US gallon is exactly 3.785411784 liters. The UK (imperial) gallon is bigger at 4.546 L; this tool uses US measures, which US labels and fuel prices refer to.
One US cup is 236.588 mL — recipes usually round it to 240 mL. Note that a metric cup (used in Australia) is 250 mL and a Japanese cup is 200 mL, so the tool's US figure is the safe default for American recipes.
One liter is 33.814 US fluid ounces. That is why a 500 mL bottle is labeled 16.9 fl oz. A fluid ounce measures volume — it is not the weight ounce.
Multiply gallons by 3.8 (or by 4 and knock off 5%). A 12-gallon fuel tank is about 45 L (exact: 45.4 L).
They double each step: 2 cups = 1 pint, 2 pints = 1 quart, 4 quarts = 1 gallon. So a gallon is 16 cups or 128 fluid ounces.

Learn more

Liters, Gallons and Cups: How to Convert Volume Units

Volume conversions are a minefield — US vs UK gallons, cups, milliliters. Here is how to convert them correctly.

Read the guide

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