The grass stops growing some time in October, the gateway turns to mud, and the farmer who sells you hay wants to know how many bales to put by. How much hay does a horse eat has a real answer: about 2% of its bodyweight a day, which for a 500 kg horse with no grazing is roughly 11 kg of hay, or two tonnes over a six-month winter before a single mouthful is wasted.
This is for the first-time owner budgeting the first winter. It covers the daily amount and where the figure comes from, the minimum you should not go below without your vet, how to turn kilograms a day into bales, how much ends up under the horse's feet, and what hay costs according to the few price reports that exist.
How much hay does a horse eat in a day?
Feed is worked out as a percentage of bodyweight. The American Association of Equine Practitioners' care guidelines, adapting the US National Research Council's 2007 tables, put a horse at maintenance at 1.5 to 2% of its bodyweight a day in total feed and a horse in work at 1.5 to 3%. University of Minnesota Extension's advice on buying hay gives 2% as the target for most horses, 1.5% for an easy keeper or an overweight horse and 2.5% for a hard keeper. In its own trial, horses eating freely from a round bale in a feeder took 2.0 to 2.4%.
Nutritionists count in dry matter, the feed with its water taken out, and that is where the arithmetic usually slips. Hay is more than 85% dry matter and haylage can be as low as 50%, according to the institute behind a 2017 European review of forage feeding, whose own examples use 90% for hay. So 2% of a 500 kg (1,100 lb) horse is 10 kg of dry matter, and 10 ÷ 0.9 is 11.1 kg, about 24 lb, of hay on the scales. The same horse on haylage needs more kilograms, not the same.
Two things the percentage cannot tell you. It needs the horse's weight, and a guess is rarely right: the AAEP calls electronic scales the most accurate method and a weight tape useful for seeing whether a horse is gaining or losing. And it needs the hay weighed rather than counted in slices. A haynet and a luggage scale will do.
The floor you should not feed below
There is a minimum, and it has moved. The European College of Equine Internal Medicine's consensus statement on gastric ulcers says horses fed hay should receive at least 1.5 kg of dry matter per 100 kg of bodyweight a day. For the 500 kg horse that is 7.5 kg of dry matter, or 8.3 kg of hay. The 2017 review raised the recommended minimum from 10 g to 15 g of dry matter per kilogram, which is the same 1.5%. Older advice still in print, Minnesota's included, says 1%.
The British Horse Society's feeding guidance draws the practical line: do not drop below 1.5% without a vet's instruction. That matters most for the overweight pony whose owner is tempted to starve it thin. Cutting below the floor is your vet's decision, not a budget's.
Why the floor exists is often overstated, so here is what the sources say. The ECEIM panel found that more than six hours between forage meals raises the likelihood of squamous gastric ulcers and that fasting is a well-described risk. It also wrote that strong evidence for free-choice forage preventing ulcers is lacking, and that starch is the more consistent culprit. A Texas study of 364 horses, published in 2001, tied colic not to the amount of hay but to a recent change in the batch of hay and to feeding from round bales. The BHS adds that enough forage satisfies the need to chew and helps prevent stereotypic behaviour. For a winter's order the lesson is plain: buy one batch if you can, and change over gradually when it runs out.
From kilograms a day to bales for the winter
Count your own days without grass. Over 180 days, the 500 kg horse on 11.1 kg a day eats 2,000 kg. That is hay eaten, not hay bought, and the gap depends on how you feed it. Minnesota's trials measured the waste:
| How the hay is fed | Hay wasted | To buy, for 2,000 kg eaten |
|---|---|---|
| Small bales, outdoors, in a feeder | 1 to 5% | 2,020 to 2,105 kg |
| Small bales, outdoors, on the ground | 13% | 2,299 kg |
| Round bale in a feeder | 5 to 33% | 2,105 to 2,985 kg |
| Round bale, no feeder | 57% | 4,651 kg |
The sum is hay eaten divided by one minus the waste: 2,000 ÷ 0.95 = 2,105 kg. Then convert to bales using the weight of the bales you are offered, because a bale is not a unit. Minnesota's own example sets a 35 lb small bale against a 50 lb one. At 50 lb (22.7 kg), 2,105 kg is 93 bales; at 35 lb it is 133. Weigh three or four before you agree a price, and ask for the price per tonne.
Storage counts as well. The same source reports 7 to 49% of dry matter lost from round bales left uncovered outdoors, against 2 to 6% indoors.
Hay quality changes how much hay to feed a horse
Two hays that look alike can feed very differently. In Minnesota's example, 18 lb of a grass hay did the work of 15 lb of a richer mixed hay. A laboratory analysis is the only way to know, and Minnesota Extension's guide to reading one puts a basic test at about $20. It reports moisture and fibre, and the sugar and starch that decide whether a hay suits a laminitic horse: Minnesota and the BHS both set that line at about 10 to 12%, above which the hay is soaked or avoided.
Moisture matters on the day you buy. The same guide gives 10 to 15% as the right range and warns that hay above 16% may mould. Dusty or mouldy hay is not cheap at any price.
How much does it cost to feed a horse through winter?
Here the evidence is thin. We found no body, in any of the ten countries we checked, that publishes what a horse owner pays for a small bale delivered to a yard. What exists are farm-gate and wholesale prices per tonne, and they are a floor under your bill, not the bill.
In the US, the Department of Agriculture's monthly price report put the average received by farmers in August 2026 at $190 a short ton (907 kg) for all hay and $152 for hay other than alfalfa. In Great Britain, the merchants' buying price for big-bale hay, ex-farm, was £106 a tonne in the week to 27 September 2026.
Run the 2,105 kg through them. It is 2.32 short tons: $353 at the farm-gate figure for non-alfalfa hay, and $696 at the $300 a ton Minnesota Extension uses in its own example for horse hay. Over six months that is $59 to $116 a month. At the British merchants' price it is £223. Expect to pay more than these for small bales, delivered and stacked.
Hard feed is the other part of the question, and for many horses the smaller part. Minnesota Extension says most classes of horse can meet all or most of their energy needs from good hay alone. Where concentrate is fed, it can dominate the bill. In a worked example from France's national horse institute, at 2014 prices, 4 kg of pellets cost €2.32 a day beside €0.63 for 7 kg of hay. That is old and French, and we found no other institute that publishes such a figure. What your horse needs beyond hay is a question for your vet.
Where we fit
Hoofine cannot weigh your hay or your horse. What it can do is put the people who sell forage in one place: the feed suppliers in the directory are there to be asked for a price per tonne and a bale weight. If your horse is at livery, check whether hay is inside the fee before you order any; what boarding really includes explains why that varies, and the boarding yards listed can be asked directly. A horse that loses weight on a sensible ration needs one of the equine vets, not simply more hay. And hay is one line of the wider budget in how much a horse costs per month.
