A recipe for baguette says 2 cups of water to 20 ounces of flour (2.5 cups), but this ratio turns out like batter. Help?

Thank you!

Just did the math and assuming 4.5 ounces per cup of all-purpose flour, 20 ounces is just under 4 1/2 cups. However, this changes with different types of flour since different flours have different densities and different weights per cup as a result.

20 ounces of flour must refer to a weight of flour not volume. By weight, 20 ounces of flour should be more like 4 cups of flour.