Horse Feed Calculator
Calculate daily feed requirements for horses from body weight, workload, and hay quality. Estimate hay, grain, water, and monthly feed costs.
Horse Feed Calculator
Calculator
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Formula: Daily Hay (lbs) = Body Weight x Hay% x Age Multiplier; Daily Grain (lbs) = Body Weight x Workload% x Age Multiplier
Worked example — Daily Hay: 20.0 lbs | Daily Grain: 7.5 lbs | Total Energy: 27.1 Mcal
Formula
Daily Hay (lbs) = Body Weight x Hay% x Age Multiplier; Daily Grain (lbs) = Body Weight x Workload% x Age Multiplier
Where Hay% is determined by hay quality (1.8-2.5%), Workload% reflects exercise intensity (0.5-1.25%), and Age Multiplier adjusts for growing (1.15x) or senior (0.9x) horses. Digestible Energy (DE) is calculated by multiplying feed weight by the energy density of each feed type.
Worked Examples
Example 1: 1,000 lb Horse in Moderate Work
Problem:A 1,000-pound adult horse in moderate work with average-quality hay. Calculate daily hay, grain, and energy needs.
Solution:Hay = 1,000 lbs x 2.0% = 20.0 lbs/day Grain = 1,000 lbs x 0.75% = 7.5 lbs/day (oats) Hay DE = 20.0 x 0.85 Mcal = 17.0 Mcal Grain DE = 7.5 x 1.35 Mcal = 10.1 Mcal Total DE = 27.1 Mcal/day
Result:Daily Hay: 20.0 lbs | Daily Grain: 7.5 lbs | Total Energy: 27.1 Mcal
Example 2: 800 lb Growing Horse
Problem:An 800-pound yearling in light work with good-quality hay. Determine feed amounts with age adjustments.
Solution:Base Hay = 800 x 1.8% = 14.4 lbs; Adjusted = 14.4 x 1.15 = 16.6 lbs Base Grain = 800 x 0.5% = 4.0 lbs; Adjusted = 4.0 x 1.15 = 4.6 lbs Hay DE = 16.6 x 1.0 = 16.6 Mcal Grain DE = 4.6 x 1.35 = 6.2 Mcal Total DE = 22.8 Mcal/day
Result:Daily Hay: 16.6 lbs | Daily Grain: 4.6 lbs | Total Energy: 22.8 Mcal
Frequently Asked Questions
How much hay should a horse eat per day?
A horse should consume between 1.5% and 2.5% of its body weight in forage (hay or pasture) daily. For a typical 1,000-pound horse, that translates to roughly 15 to 25 pounds of hay per day. The exact amount depends on the quality of the hay, the horse's activity level, its metabolic condition, and whether supplemental grain is being fed. Higher-quality hay like alfalfa or well-cured timothy provides more digestible energy per pound, so the horse may need slightly less volume. Horses with easy-keeper tendencies may do well on the lower end, while hard-keepers or lactating mares may need closer to the upper limit.
How does workload affect a horse's feed requirements?
Workload significantly impacts how much energy a horse needs beyond its baseline maintenance requirement. Light work such as occasional trail riding increases energy needs by roughly 25% above maintenance. Moderate work like regular schooling or light competition raises needs by around 50%. Heavy work including intense training, racing, or frequent competition can increase caloric requirements by 75% to 100%. Most of these additional calories should come from concentrated feeds like grain or fat supplements rather than simply feeding more hay. It is important to increase feed gradually as workload increases and to reduce it promptly when the horse is rested to avoid metabolic issues or excessive weight gain.
What is the difference between oats, corn, and sweet feed for horses?
Oats are the safest and most traditional grain for horses because they have a high fiber content relative to other grains and are less likely to cause digestive upset. They provide moderate energy at about 1.35 Mcal of digestible energy per pound. Corn is much more energy-dense at roughly 1.6 Mcal per pound, making it suitable for hard-working horses, but it must be fed carefully because overfeeding can cause colic or laminitis. Sweet feed is a commercial mix of grains bound with molasses that provides balanced nutrition and high palatability. However, the sugar content in sweet feed can be problematic for insulin-resistant horses or those prone to metabolic syndrome.
How much water does a horse need daily?
An average horse at rest needs approximately 5 to 10 gallons of water per day, which equates to about 0.5 gallons per 100 pounds of body weight. However, water requirements can double or even triple during hot weather, heavy exercise, or lactation. A horse performing moderate to heavy work in warm conditions may drink 15 to 20 gallons daily. Access to clean, fresh water at all times is essential for preventing dehydration and impaction colic. Horses often reduce water intake during winter when water sources are cold, so providing slightly warmed water in freezing conditions can help maintain adequate hydration levels throughout the year.
How should I adjust feed for a growing foal or senior horse?
Growing foals and yearlings have higher protein and mineral requirements compared to adult horses because they are building bone, muscle, and connective tissue. They typically need diets with 14% to 16% crude protein, along with adequate calcium and phosphorus in the correct ratio of roughly 2:1. Overfeeding energy to young horses can cause developmental orthopedic diseases, so controlled growth is important. Senior horses over 20 years often have reduced digestive efficiency due to worn teeth and decreased gut function. They benefit from easily digestible feeds, senior-formulated pellets, soaked hay cubes, and possibly additional fat supplementation. Monitoring body condition score regularly helps ensure proper nutrition at every life stage.
How do I estimate body weight if I do not have a livestock scale?
The standard field method uses a heart-girth and body-length measurement in inches: weight in pounds is approximately girth squared, multiplied by body length, divided by 330. Girth is measured around the barrel just behind the elbow and withers; length runs from point of shoulder to point of buttock. A horse with a 74-inch girth and a 66-inch length gives 74 x 74 x 66 / 330, about 1,095 pounds. A weight tape is quicker but less accurate on very stocky or very fine-boned types.
Why does the forage percentage fall as hay quality improves?
The requirement is for digestible energy and fibre, not for bulk. Good, well-cured hay carries roughly 1.0 Mcal of digestible energy per pound against about 0.7 Mcal for poor, stemmy, over-mature hay, so fewer pounds meet the same energy target. The calculator reflects this by using about 1.8% of body weight for good hay and 2.5% for poor hay. Never drop total forage below roughly 1.5% of body weight, because gut fill and chew time matter for hindgut function regardless of calories.
Why should concentrates be split into several small meals?
The equine stomach is small and starch that escapes small-intestinal digestion ferments rapidly in the hindgut, dropping pH and raising the risk of colic and laminitis. A widely used working limit is about 0.5% of body weight of concentrate per meal, roughly 5 pounds for a 1,000-pound horse, so a 7.5-pound daily ration is better fed as two meals. Feeding forage first also slows the passage of grain, and any increase in concentrate should be phased in over a week or more.
What does the daily Mcal figure represent and how do I check it is right?
Mcal here means megacalories of digestible energy, the energy remaining after faecal losses, which is the unit equine ration tables use. The total sums hay pounds times hay energy density and grain pounds times grain energy density. Because energy density varies by cutting and storage, treat it as a starting ration and verify against the horse itself using body condition scoring on the 1 to 9 scale, aiming for about 5 for most working horses, and re-weighing monthly. Rising or falling condition means adjust before recalculating.
How much salt does a horse need, and when are electrolytes needed instead?
Plain sodium chloride is the mineral most often short in a forage-based diet: about 1 ounce a day suits a light horse and roughly 2 ounces a horse of 900 pounds or more at rest. Sweat carries sodium, chloride and potassium, so a horse in heavy work or hot weather can lose far more and benefits from a balanced electrolyte supplement rather than extra salt alone. Always offer free-choice salt and unlimited water; electrolytes given to a dehydrated horse with no water available worsen the deficit.
References
Reviewed for accuracy by Daniel Agrici, Founder & Lead Developer · Editorial policy
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