According to various internet sources, a 10ft square patch will produce enough for 1 loaf. I have not tested that yet, I’m still trying to get back more than what I planted.
Other seeds fell on good soil and produced grain, some a hundredfold, some sixty, some thirty.
How are you planting? Drill; broadcast; something else?
I've used my tiller to shallowly till in broadcast seed--HRW--with good results.
Better result was deep tilling, then using a hand-push grass-seed spreader, set to a recommendation from the manufacturer; I think it was an old Scott, with about a 3' width. That was for a 40 X 110' plot: never again!
Hand harvesting; hand threshing; hand winnowing...then raking & stacking the straw. From that, we ended up with several gallon jars & some 5 or 6-quart ice cream buckets full of clean wheat seed. I still have a 32 quart plastic tub full of mostly unthreshed heads left.
This year, I did thresh out a bit over a quart of seed, enough for a 25 X 40' plot. I used the tiller to plant that into a 20 X 35' plot as mainly a green manure crop. It germinated ~75%, which is fairly well, considering the seed was several years old & had just been left in the plastic tub in an a open faced barn.
I plan on letting enough to mature for new seed, but will plow the rest under in the spring, while still growing. So far, it's about 3-4" tall. I've also used the tiller method to grow both small amounts of rye & barley with goo0d results & return.
Another one is Home Grown Whole Grains; Grow Harvest & Cook Wheat, Barley, Oats, Rice, Corn, & More by Sara Pitzer. She gives a figure of "up to" 20 pounds from a 10 X 10 plot; that seems like a highly optimistic number, and is way higher than Logsdon's 5.5 lbs.
Hope this helps.