Convert l to qt

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 quart is a quarter of a gallon, which is where the name comes from. Like the pint and the gallon it carries the US-versus-imperial difference with it.

The factor is 1.056688, and almost nobody carries that around. Rounded to 1.06 it is off by 0.31 % — 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 quart is two different sizes wearing one name. This page uses the US one, which is 0.94635 l; the imperial one still used in the UK and Ireland is 1.13652 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 1.0567 US quarts. Of every customary unit on this site, the quart is the one closest to a metric counterpart, and that proximity is the problem rather than a convenience: two units within six per cent of each other get swapped freely, and nothing about the answer looks wrong when they are.

The error is also one-directional, which makes it accumulate rather than average out. Reading a quart as a litre always overstates the American capacity, so a 12-quart pot taken as twelve litres is credited with 640 ml it does not have — most of a large mug, on a container people buy for its exact size.

Stock pots, slow cookers, food containers, coolers and countertop appliances are all sold by the quart on the US market, and the ladder runs in whole numbers: 2, 4, 6, 8, 12, 16. In litres those are 1.89, 3.79, 5.68, 7.57, 11.36 and 15.14, which is why an American range relabelled for a metric market looks as though somebody picked the sizes at random.

Going the other way, metric capacities are chosen at round litres and come out fractional in quarts: a 5 litre pot is 5.28 quarts and a 3 litre one is 3.17. Comparing a metric pot against an American rating therefore always involves a fraction on one side, and the fraction is where a size that looked equivalent turns out not to be.

An imperial quart is 1,136.5225 ml, which is 20.1 per cent more than the American one and 13.7 per cent more than a litre. It is a quarter of the imperial gallon, in the same way the US quart is a quarter of the US gallon, and the whole difference between the two gallons is inherited straight down.

In practice it appears on older British documentation and in Commonwealth sources that predate metrication rather than on anything currently on sale. The tell is usually the company it keeps: a document quoting pints of 568 ml is working in imperial throughout, and its quarts are imperial quarts whether or not it says so.

The United States keeps a dry quart for produce sold by bulk — berries, tomatoes, shellfish — and it is 1,101.22 ml, about 16 per cent larger than the liquid quart this page converts. It descends from the bushel rather than from the gallon, which is why it is not a simple fraction of anything on the liquid side.

It matters only in a narrow context and it fails quietly when it does. A dry quart mistaken for a liquid one is out by roughly the same proportion as the imperial-versus-US gap, so the error looks like the familiar one and gets filed as that, and the correction applied is the wrong correction.

A metric capacity quoted as 4.7 litres was almost certainly five quarts, and one quoted as 5.7 was six. Round metric numbers with a single decimal, sitting a little below a whole litre, are the signature of a customary size that has been translated once and rounded on the way.

Recognising that changes what the number means. A container marked 4.7 litres holds a nominal five quarts and was built to that; treating 4.7 as its design figure and comparing it against a 4.7 litre metric product compares a rounded label with a real capacity. Where it matters, convert back and see whether the original was a whole customary number.

The customary side is easy to move around in once the litre figure is a quart figure, because everything above and below is a whole-number step. Four quarts make a gallon, two pints make a quart, and 32 US fluid ounces make a quart. So 5.283 quarts is also 1.32 gallons, 10.57 pints and 169 fluid ounces, with no further conversion factor involved.

That is the reason an American specification will move between those units mid-document without explanation, and why a metric reader keeps meeting the same capacity under three different names. Converting the litre figure to quarts once and stepping sideways from there is less work than converting it separately into each.

Two decimal places is generous for a container. A pot rated at six quarts is not a calibrated vessel: the rating usually refers to the volume to the brim, the usable capacity is smaller, and manufacturers differ on which they quote. A conversion carried to four decimals is describing a number more carefully than the object it names.

Where the extra digits do earn their place is in totals. Adding several containers, or sizing a batch against a set of them, compounds whatever was rounded at each step, and a per-container error of a few millilitres becomes a visible shortfall by the tenth. Round at the end, and only once.

Once a litre is 1.0567 quarts, every other American volume follows without a second factor, because the customary units below the gallon are whole-number divisions of each other. A litre is 0.2642 gallons, 1.0567 quarts, 2.1134 pints, 4.2268 cups and 33.814 fluid ounces, and each figure is the one above it doubled, doubled again, or multiplied by eight.

Having the ladder in one place is what makes an American specification readable, because it will move between those units without warning and expect the reader to keep up. A rating in quarts, a fill instruction in cups and a dose in fluid ounces can all describe parts of the same container, and a metric reader who has converted the litre once does not have to convert it again for each. The one figure worth committing to memory is the fluid ounce count, because 33.814 to the litre is the rung the others are all derived from and the one an American label is most likely to print.