Convert l to pt

A litre is a thousand cubic centimetres. It is not strictly an SI unit — the SI unit of volume is the cubic metre — but it is accepted for use with SI and is what fuel, drinks and engines are measured in.

A US pint is 473 ml and an imperial pint is 568 ml — a fifth larger. This is the single most consequential difference between the two systems for anybody following a recipe or ordering a drink.

The factor is 2.113376, and almost nobody carries that around. Rounded to 2.1 it is off by 0.63 % — which stays invisible on small numbers and turns into a whole unit somewhere around 1,000 l.

That is the number worth knowing before you round: not the error itself, but where it stops being ignorable. Below that point the shorter factor is the sensible one; above it, use the field above, which never rounds until it prints.

The US pint is two different sizes wearing one name. This page uses the US one, which is 0.47318 l; the imperial one still used in the UK and Ireland is 0.56826 l — larger by 20.1 %.

That gap is the awkward size: far too big to ignore in a recipe, and far too small to spot from the answer alone. If your figure came from a British source, take the second number, and note that the fluid ounce is the one unit here where the imperial measure is the smaller of the two.

A litre is 2.1134 US pints and 1.7598 imperial pints, and there is no way to give a single correct answer without saying which pint is meant. The page converts the American one, because that is the customary unit this site uses throughout, and the British figure is the one to take when the drink, the container or the recipe came from the UK or Ireland.

The size of the gap is what makes it dangerous rather than obvious. A fifth is small enough that a glass of one looks like a glass of the other across a bar, and large enough that counting a keg out in the wrong pint miscounts it by seventeen drinks in a hundred. Where the number is going to be used to buy, price or stock anything, the version of the unit is not a detail.

Britain kept the pint by statute rather than by nostalgia. Draught beer and cider have to be sold in a third of a pint, a half, two-thirds or multiples of a half, and the glass itself has to be a certified measure carrying a verification mark — which is why a British pub glass has a line or a stamp on it and an American one usually does not. Milk sold in returnable containers may also be quoted in pints.

That legal status is the reason 568 ml is a fixed quantity in a country that is otherwise metric. The keg it is poured from is labelled in litres, the duty is calculated on litres of alcohol, the brewery’s recipe is in litres — and the measure handed across the bar is imperial and enforceable. Converting between the two is therefore a routine part of running a bar rather than a curiosity.

The same order gets you 568 ml in a British pub and 473 ml in an American bar: about four fifths of the drink, for a word that does not change. Over an evening of four the difference is 380 ml, which is most of another British pint. It also runs through the pricing — a price per pint compared across the two countries is comparing two different volumes before any currency is involved.

The American glass makes it slightly worse rather than better. A 16-ounce shaker glass is exactly a US pint filled to the brim, so a pour with any head on it is short of the nominal measure, and there is generally no certification behind the glass to say otherwise. If a volume matters — for tracking intake, for a recipe, for a duty calculation — take it from the container rather than from the glass.

The standard European keg of 50 litres holds about 88 imperial pints or 105.7 US pints; the 30-litre keg holds 52.8 or 63.4. A British cask firkin is 9 imperial gallons, 40.9 litres, which is 72 imperial pints exactly — the roundness is the giveaway that the cask was sized in gallons and the litre figure is the conversion. A 5-litre mini keg is 8.8 imperial pints or 10.6 US.

Nobody gets the full count out of a keg. Line cleaning, the first unsettled pints and the sediment left at the bottom take a few litres out of every container, and a cellar planning on the arithmetic figure will run short. Treat the converted number as the ceiling and work down from it, which is exactly how the trade quotes yield rather than volume.

Homebrew recipes are generally written for a 19- or 23-litre batch, which is 33.4 or 40.5 imperial pints, or 40.2 and 48.6 US. Those are the numbers that decide how many bottles to sterilise: at 500 ml a bottle a 23-litre batch fills 46, and at a British pint a bottle it fills 40. Working in litres until the last step and converting once is much less error-prone than brewing in pints.

The transfer losses matter here for the same reason they do in a cellar. Trub, hop material and the liquid left behind in a siphon typically account for a litre or two of a domestic batch, so a 23-litre boil is not 23 litres of bottled beer. Converting the volume actually racked, rather than the recipe’s nominal figure, is the difference between the bottle count being right and being two short.

British milk bottles come in 1.136, 2.272 and 3.408 litres, which look arbitrary until you divide by 0.56826 and get two, four and six pints. The containers were designed around the imperial pint and the metric labelling was added on top, so the odd decimal is the honest translation of a round number rather than a strange choice of size.

The same thing happens in recipes on both sides of the Atlantic. A British recipe asking for a pint of milk means 568 ml; an American one means 473, and often means it as two cups. Where a recipe gives both a pint and a millilitre figure, the millilitre figure settles which pint the writer had in mind, and it is worth reading before doubling anything.

For US pints, double the litres and add a tenth: 3 litres is 6 plus 0.6, about 6.3 pints against 6.34. For imperial pints, double and take an eighth off: 3 litres is 6 less 0.75, about 5.25 against 5.28. Two rules, both accurate to about half a per cent, and the difference between them is the whole US-imperial question in a form you can hold in your head.

Backwards, a British pint is a bit over half a litre and an American one a bit under. Eight British pints is 4.5 litres and eight American pints is 3.8, which is the same statement as the two gallons and is easier to remember in drinks than in gallons. Use the field above when a stock count or a duty figure has to survive somebody checking it.