The short answer: 1 litre = 33.814 fluid ounces. That single number is the whole conversion — multiply any amount in litres by 33.814 and you have the amount in fluid ounces. It is an exact conversion between two units of volume in the US customary system, so there is no estimating, no density to look up and no ingredient that changes it. A litre of water, a litre of milk and a litre of stock are all 33.814 fluid ounces.
Unlike a conversion between cups and grams, which depends on what is in the cup, this one has a single right answer. A litre is a defined volume and a fluid ounce is a defined volume, so the ratio between them is fixed by the definitions themselves. That makes it reliable in a way that ingredient conversions are not — and it means the table on this page is correct for every liquid, from water to cream to stock, without exception.
Conversion table
| Litres | Fluid ounces |
|---|---|
| ¼ litre | 8.4535 fluid ounces |
| ½ litre | 16.907 fluid ounces |
| ¾ litre | 25.3605 fluid ounces |
| 1 litre | 33.814 fluid ounces |
| 1.5 litres | 50.721 fluid ounces |
| 2 litres | 67.628 fluid ounces |
| 3 litres | 101.4421 fluid ounces |
| 4 litres | 135.2561 fluid ounces |
Read the table in either direction. Going from litres to fluid ounces, multiply by 33.814; going back, divide by 33.814 or multiply by 0.0296. The middle rows are the ones recipes use most — 1 litre is 33.814 fluid ounces, and 2 litres is 67.628 fluid ounces. If your amount is not in the table, multiply it by 33.814 and you have the answer. For a quick check: 1 litre is 33.814 fluid ounces, 2 litres are 67.628 fluid ounces, and 10 litres are 338.1402 fluid ounces.
Worked examples
A buttercream frosting that needs ¾ litre. The recipe calls for ¾ litre and your jug is marked in fluid ounces. That is 25.3605 fluid ounces — pour to that line and you have the right amount. If you double the recipe for a crowd, you need 1.5 fluid ounces, which is 50.721 fluid ounces. The conversion itself never changes with the ingredient: whether the buttercream frosting uses milk, water or melted butter, ¾ litre is always 25.3605 fluid ounces. What changes is only the weight, never the volume.
A small batch, halved. A banana bread recipe makes too much, so you halve it. The original uses 1.5 litres; halved, that is 0.75 litre, which is 25.3605 fluid ounces. Small amounts are where conversion errors hurt most, because a 10% error in a small amount of liquid is a bigger share of the recipe. When the halved amount is awkward, measure it in fluid ounces — the finer unit gives you a cleaner number.
Baking, where precision matters. A cake batter that needs 1.5 litres of milk has no room for guessing: that is 50.721 fluid ounces. In baking, liquid is a structural ingredient, and a 10% error changes the crumb. If your recipe gives the liquid in fluid ounces and your cups are in litres, convert before you start, not while the oven is heating. And if the recipe also gives a weight in grams, use the weight — it is the most accurate measure of all.
How the conversion works
The US litre is defined as 1000 ml, and the fluid ounce is defined as 29.5735 ml. Divide the first by the second and you get 33.814 — that is the whole derivation, and it is why the conversion is exact rather than approximate. No kitchen experiment was needed to establish it; the units were defined this way, so the ratio follows from the definitions. That is also why the same factor appears in every reliable conversion chart: there is only one right answer, and every source that uses US customary units agrees on it.
The one thing to check is which litre your recipe means. This page uses the US customary litre throughout. A metric cup is 250 ml, an imperial cup is 284 ml, and older recipes sometimes use a 'cup' that means whatever cup the writer had in the cupboard. If a recipe from outside the US gives an amount that looks wrong after converting — a cake with far too much liquid, a soup that is far too thin — the cup is the first suspect. Convert the recipe to grams once, write the grams on the recipe card, and the question never comes up again.
Rounding deserves a note too. The exact factor is 33.814 to four decimal places, and the full value runs further (1000.00 ml divided by 29.57 ml). For everyday cooking, rounding to two or three significant figures is fine: a 1% rounding error is invisible in a soup and barely noticeable in a cake. But round only at the end. If you round the factor and then multiply by a large amount, the rounding error grows with the amount — so keep the full factor through the calculation and round the answer, not the factor.
Volume is not weight
A conversion between two volume units is the same for every ingredient, but a conversion between volume and weight is not — and confusing the two is the most common conversion mistake in cooking. A cup of all-purpose flour weighs about 120 g spooned and levelled (King Arthur Baking), a cup of granulated sugar about 198 g, a cup of butter about 227 g, a cup of milk about 244 g (USDA), and a cup of honey about 336 g. All of those weights are approximate, because they depend on how the ingredient is measured: flour is spooned and levelled, brown sugar is packed at about 213 g a cup, and honey is poured.
Flour weight is the most disputed conversion in baking. King Arthur Baking lists 120 g per cup spooned and levelled, while other sources quote 125 g, 130 g and up to 142 g for a scooped cup. We use the King Arthur spooned-and-levelled value as primary, and the gap is a warning: if you scoop flour instead of spooning and levelling it, you can add 20 g or more per cup, which is enough to make a cake dry. Granulated sugar carries a smaller dispute — King Arthur lists 198 g per cup and the USDA rounds it to 200 g, a difference of rounding rather than a real disagreement. When a recipe matters, verify with a kitchen scale: weigh the ingredient instead of measuring it by volume, and every dispute on this page disappears.
Measuring accurately
The conversion is exact, so any error in your cooking comes from the measuring, not the maths. Use a liquid measuring jug for liquids and dry cups for dry ingredients — a jug's wide top and spout make it hard to level a dry ingredient, and a dry cup's flat rim makes it hard to read a liquid meniscus. Read a jug at eye level, on a flat surface, with the liquid settled; reading it from above makes the meniscus look higher than it is. For spoon measures, level with the back of a knife: a heaped spoon can hold half as much again as a level one, which is a 50% error in a teaspoon of baking powder. Measure over the sink or the ingredient's own container, never over the mixing bowl, so a spill does not go into the batter. And if you own a kitchen scale, use it for anything that matters — weighing is more accurate than any volume measure, and it removes the conversion entirely. Keep your measuring cups together as a set, because cups from different sets are not always the same size, and a mixed set is a quiet source of error in every recipe you cook.
Frequently asked questions
Does temperature change the conversion?
No, not in any way that matters in a kitchen. Liquids expand slightly when heated, so a cup of boiling stock is a fraction of a percent larger in volume than a cup of cold stock, but the difference is far smaller than ordinary measuring error. Measure liquids at room temperature where you can, and never worry about temperature when converting between volume units.
How many litres are in 1 fluid ounce?
0.0296 litre — the reverse of the main conversion. Divide the number of fluid ounces by 33.814, or multiply by 0.0296. For example, 0.1183 litre is 4 fluid ounces. Use the reverse direction when a metric recipe gives you fluid ounces and your cups are in litres.
How do I convert litres to fluid ounces without a calculator?
Multiply by 33.814; for a quick mental estimate, round the factor to a friendly number and accept a small error. If the factor is larger than 1, break the amount into whole units and fractions — for example, convert 2 litres and a half litre separately and add them. If the factor is smaller than 1, remember that one fluid ounce is 0.0296 litre, which is often easier to picture. For anything that matters, a phone calculator or the table on this page is faster and more accurate than mental maths mid-recipe.
How many litres are in 67.628 fluid ounces?
Two litres — because 67.628 fluid ounces divided by 33.814 is 2. Doubling is the easiest check on any conversion: if doubling the input doubles the output, the factor is being applied correctly. Use it to sanity-check your maths whenever a converted amount looks surprising.
How many fluid ounces are in 3 litres?
101.4421 fluid ounces. Multiply 3 by 33.814. Larger amounts like this are where a jug marked in fluid ounces earns its keep — counting them out in litres means many pourings and many chances to lose count.