My experience: 5 acres of minimal pasture (as in drought conditions, cattle aren't grazing much at all), 3 mature Dexters + 2 calves... One EXCELLENT quality 1000lb Kansas Prairie (or brome - we fed both) round bale (no weeds, no mold, cut at correct maturity, ~12% protein) would last ~2 weeks, give or take. Very little wasted, bale was in a feeder, any excess on the ground was picked up and re-fed 2x daily.
So, if I count the 2 calves as 1 unit, that would be approx. 17lbs of hay per animal per day... If you are talking small square bales - that could be half a bale, or it could be less than a quarter of a bale. It all depends on how much the small square bale weighs, which can vary A LOT.
Which is why you should always WEIGH your flakes/bales until you have trained your arms to know approx. how much you are feeding. I have small squares in my barn now - 3 different varieties of hay, and from different farms. Some bales are barely 30lbs., and some are 70+. So I can't just feed "half a bale" or "3 flakes" each day and be feeding the same weight. But I digress.. I am just a stickler about feeding by weight and not volume...
If you want to go thru a lot of hay.... Feed about 100 head of Herefords (mixed herd cows-heifers-calves-2 overworked bulls) through the winter when the pasture isn't producing. It'll keep ya busy,