Hay Needs Calculator
Estimate how much hay your horses, cattle, goats, sheep, and alpacas need for the season, in pounds, tons, bales, dollars, and barn space, with waste built in.
Free · no account · works on mobile · embeddable
Best for anyone buying or putting up hay for a mixed group of horses and livestock. Updated .
Animals on hay
Leave headcount at 0 for species you do not keep. Intake presets are as-fed planning rates from extension guidance; replace them with your own feeding records.
Season, waste, and bales
Hay to put up
Fed lb per day = head × body weight × intake %. Buy lb = fed × (1 + waste %). Bales = total lb ÷ bale weight, rounded up. Storage = total lb ÷ stacked density. Planning estimate: hay quality, weather, pregnancy, and lactation all move real intake, and it is not a ration or nutrition tool.
About the hay needs calculator
Running out of hay in February is expensive; buying twice what you need ties up cash and barn space. This calculator estimates the season's hay from the animals you actually have. Enter headcount and average weight for each species, keep or adjust the intake rate, then add feeding days, waste, bale weight, and price. It returns pounds fed per day, pounds to buy per day and for the season, tons, bales, cost, and the stacked storage volume the hay will take.
It works for horses, cattle, goats, sheep, and alpacas at once, so a small mixed farm can plan one hay order.
How much hay an animal eats
Extension guidance sizes hay by body weight. Maryland Extension says horses should consume 2% of their body weight in hay per day, so a 1,000 lb horse eats about 20 lb. For a cow-calf herd the same source uses 1.5 to 2.5% of body weight on a dry matter basis, toward the high end for good hay, and Nebraska Extension puts a lactating cow on average hay near 2.3% dry matter, about 2.6% as fed; the calculator's cattle preset is 2.5%. Ohio State Extension puts sheep and goats at 2 to 4% of body weight, so the presets use 3%, and Rutgers puts llamas and alpacas at 1.8 to 2.0%, so alpacas use 2%.
These are planning rates, not rations. Pregnancy, lactation, cold, poor hay, and how much pasture is still available all move real intake. After one season, divide bales fed by head and days and enter your own rate.
Waste, bales, and barn space
Hay is lost in storage and at the feeder. Maryland's horse example adds 5% storage and 5% feeding waste; Minnesota Extension measured feeding waste of 1 to 13% for small square bales depending on feeder type, and outdoor round bales can lose far more. The calculator multiplies fed pounds by (1 + waste %), so 15% waste means buying 15% more than the animals eat. Bales are rounded up to whole bales and priced at your per-bale cost.
Storage uses stacked density. Missouri Extension allows 250 cubic feet per ton of small square bales, which is 8 lb per cubic foot, and Iowa State gives 6 to 8 lb per cubic foot for small squares and 10 to 12 for large rounds. Change the density if you stack rounds or know your bales are light.
Worked example: a small mixed farm
Two 1,000 lb horses at 2% eat 40 lb a day, three 1,200 lb cattle at 2.5% eat 90 lb, and five 150 lb goats at 3% eat 22.5 lb, for 152.5 lb of hay fed per day to 10 animals. With 15% waste that is 175.4 lb to buy per day, or 24.6 bales a week at 50 lb per bale. Over a 150-day feeding season the animals eat 22,875 lb, and you need to buy 26,306 lb, about 13.2 tons: 527 bales, which at $8 a bale costs $4,216, or $28.11 a day. Stacked at 8 lb per cubic foot the hay takes about 3,288 cubic feet, roughly a 12 by 34 foot stack 8 feet high.
Sources
- University of Maryland Extension, Calculating your horse's winter hay needs. Horses should consume 2% of body weight in hay per day; the worked example adds 5% storage and 5% feeding waste and uses a 40 lb bale. Accessed Sep 4, 2026.
- University of Maryland Extension, Estimating winter forage needs of the cow-calf herd. Cattle consume around 1.5 to 2.5% of body weight per day on a dry matter basis, higher for better hay; its example uses 2% and 15% total losses. Accessed Sep 4, 2026.
This calculator gives planning estimates from the numbers you enter. It is not accounting, tax, veterinary, or legal advice. Replace the defaults with your own farm records whenever you have them.
Frequently asked questions
How much hay does a horse eat per day?
About 2% of body weight, so 20 lb a day for a 1,000 lb horse and roughly 600 lb a month. Over a 120-day winter that is 2,400 lb before waste, about 60 bales at 40 lb or 48 at 50 lb.
How much hay does a cow eat per day?
Roughly 2 to 2.6% of body weight as fed depending on hay quality and whether she is lactating. A 1,200 lb cow on average hay eats about 30 lb a day, so a 150-day winter needs about 4,500 lb, or 2.25 tons, per cow before waste.
How many bales of hay do I need for the winter?
Total pounds to buy divided by your bale weight. Weigh a few bales first: small squares vary from 40 to 70 lb, and a 20% weight difference is a 20% error in your bale count. The calculator rounds up to whole bales.
How much waste should I plan for?
Ten to twenty percent is a reasonable planning range for hay stored under cover and fed in a feeder. Minnesota Extension measured 1 to 13% feeding waste for small squares by feeder type, and feeding on the ground or leaving round bales uncovered outside pushes losses much higher.
How much space does a ton of hay take?
About 250 cubic feet for small square bales stacked tight, so 10 tons needs about 2,500 cubic feet, or a 12 by 26 foot area stacked 8 feet high. Large round bales are less dense and need about 310 cubic feet per ton.
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