Convert quarts to cups (qt to cup)

One US quart is exactly 4 US cups. That ratio belongs to the customary system itself and is much older than any link to metric: the 1959 international yard and pound agreement later fixed the yard and the pound against the meter and the kilogram, but it left the ratios between customary units (feet to the yard, ounces to the pound, cups to the gallon) exactly as they were.

Worked through: 2 qt x 4 = 8 cup.

Going the other way, one US cup is 0.25 US quarts.

To convert without a calculator, multiply by 4. Rounding that to 4 is within 0% for most purposes.

Four cups to a quart. The US volume system doubles at every step (two cups to a pint, two pints to a quart, four quarts to a gallon), which is why kitchen quantities scale without arithmetic and why recipes halve so cleanly.

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