Different brands sell bottles of brake fluid with different sizes. Please see the chart.
The ATE comes in 33.8 oz cans = 1 Litre. I believe this is the link for information I used when I was trying to determine how much to purchase for a complete flush of the brake system. I had the Ford Dealer perform the 1st flush for sure, and I think the 2nd flush and then I installed the Vorshlag lines with my left over fluid. How much brake fluid to flush system? - MustangForums.com
I am pretty sure both flushes used at least 1.5 litres = 50.7 oz. That ends up being about 3.2 pints at 16 oz per pint.
So I still believe you need to purchase 2 quarts or 2 litres for flushing to be on the safe side. I went even safer going with 3 since it was my first time and it worked out great the 2nd time since I lost fluid when I installed the lines.