US cups to liters (cup to L)

One US cup is exactly 0.2365882365 liters. That is a definition rather than a measurement: the imperial and US customary units were fixed against metric ones by the 1959 international yard and pound agreement, so this factor does not drift and will not be revised.

Worked through: 4 cup x 0.236588236 = 0.946353 L.

Going the other way, one liter is 4.226752838 US cups.

For mental arithmetic: Multiply by 0.24, or think of four cups as just under a liter.

A liter is 4.23 US cups, which makes it the useful anchor for anything poured by the jug: a 2-liter bottle is about 8.5 cups and a 1-liter carton is just over four. The trap is the coffee maker. The 'cups' on a carafe are not measuring cups. They are typically 5 or 6 fluid ounces each rather than 8, so a 12-cup machine holds about 1.8 to 2.1 liters and not the 2.8 a straight conversion would suggest. Recipes from Australia and New Zealand use a metric cup of exactly 250 ml, so four of theirs is exactly a liter and four of the American ones is 946 ml.

Precision is worth matching to the input. A measurement given as 0.5 cup carries one or two significant figures, and reporting its conversion to six implies a precision the original never had.