Start with what each horse actually eats
A hay budget built on bales per week falls apart the moment bale sizes change, so build yours on pounds per horse. A horse with no pasture to pick at needs forage at roughly two percent of body weight a day: about 20 pounds for a 1,000-pound horse, nearer 24 for a big warmblood and 16 for a small pony cross. Easy keepers at maintenance sit at the lower end of that range, while older horses, hard keepers and anything still in work sit higher, because hay is also their heating fuel once temperatures drop. Weigh a few bales from your current stack on a bathroom or luggage scale rather than trusting the seller's estimate, since a five-pound error per bale compounds across a whole winter.
Count your winter honestly
Walk your fields and decide when grazing genuinely stops contributing, not when you wish it stopped. Horses cropping dormant pasture to the roots are eating very little and damaging the sward, so most owners should count full hay feeding from that point until spring growth is several inches tall and firm underfoot. Multiply each horse's daily pounds by that number of days. A herd of four average horses fed for 140 days at 20 pounds each needs about 11,200 pounds, or 5.6 tons, before any allowance for waste. Writing the herd down horse by horse, with the seniors and youngsters on their own lines, stops the common mistake of budgeting every animal as the average one.
Add the cushion, then buy by the ton
No stack feeds out at one hundred percent. Round bales stored outside lose their outer layer, bottom bales pick up moisture, and horses bed down on a share of what you fork out. A cushion of ten to fifteen percent on top of the calculated tonnage covers most of that, and it is far cheaper bought in autumn than in the emergency load everyone is chasing in February. When you compare suppliers, convert everything to price per ton using your weighed bale average. A cheap small bale can cost more per pound of actual hay than a dearer heavy one, and the per-ton figure is the only honest comparison between square and round bales.
Track the stack as winter unfolds
A budget is only useful if you check it against reality. Count bales weekly, or mark the stack each time a load comes off it, and compare what remains against the days left to spring. If the stack is shrinking faster than the plan, you can adjust early: tighten up feeding waste with nets or feeders, separate the horse who is scattering his ration, or order the top-up load while suppliers still have choice. Horses that lose condition in late winter are usually telling you the budget ran short weeks earlier, not that the hay suddenly failed.
Setting each horse's daily hay weight as a recurring duty in KinsLe's Care Teams means everyone feeding that week works from the budgeted ration, and completed feedings are timestamped, so the plan on paper and the hay leaving the stack stay the same thing.