But it would be easier to guess if you told us the final dough weight. A full sized rimmed baking sheet for most residential cooks is technically a half sheet . The pan you describe as 9x13 I would call a quarter sheet pan. But my experience would say that any final dough weight of about 1000g would produce a half sheet of focaccia (a full sized sheet for home cooks). I ll go one step further and suggest that one full recipe for Basic Country Bread dough produces two loaves, which in my humble opinion would fill a professional sheet pan (twice as much as what we use at home). In short, I suspect halving the recipe would fill a sheet pan most home cooks consider full sized (and two of your 9x13 pans)