Horse Hay Calculator (Annual Tons, Bales, Barn Storage Space & Cost)
Plan a year of hay for your horses: pounds per day from body weight and the share of the diet that is hay, days off pasture, total tons and bales (small squares, large squares or rounds) with waste, the barn floor area and stack height needed, and the cost with a comparison of bale types by price per ton.
How it works
hay per horse per day = body weight × intake % × hay share · annual = daily × horses × days on hay ÷ (1 − waste) · bales = pounds ÷ bale weight; storage = bales × bale volume × 1.1 ÷ stack height · $/ton = price per bale ÷ bale lb × 2,000
Horses eat roughly two percent of their body weight in forage every day, and when pasture is gone that is all hay. Multiply by the days off grass and the herd, add the hay that is trampled, soiled or blown away — a bigger number than most owners expect — and the result is tons, bales, a barn footprint and a bill. Buying by the ton at harvest and cutting waste with slow feeders are the two levers that change the total; the calculator shows both.
Worked example
Three 1,100 lb horses eating 2% of body weight in hay for 240 days: 22 lb each, 66 lb a day, 7.9 tons eaten; with 12% waste about 9.0 tons to buy — 360 small squares of 50 lb at $9 is $3,240 ($360/ton). Stacked 8 ft high that is about 260 ft² of dry floor for the whole year, and about 30 bales a month.
Frequently asked questions
How much hay does a horse eat per day?
About 1.5–2.5% of body weight in forage: 15–25 lb for a 1,000 lb horse, more in cold weather, for hard keepers and for lactating mares. Feed by weight, not by flake — flakes vary from 2 to 6 lb.
How many bales of hay per horse per year?
A 1,100 lb horse on hay year-round eats about 4 tons; with 15% waste you buy 4.7 tons, about 190 small squares of 50 lb or 10 round bales of 900 lb. With six months of pasture, roughly half that.
How much space does hay take?
A 50 lb small square is about 5 cubic feet; a ton of small squares stacked takes 200–230 cubic feet, so 10 tons stacked 8 ft high needs about 300 square feet of floor. Round bales are denser but awkward to stack more than two high.
Related calculators
Equine figures are planning estimates from common husbandry references (NRC 2007, extension services). Individual horses, forage quality, climate and workload vary — weigh hay, body-condition score regularly and work with your vet, farrier and nutritionist.