Horse Feed Calculator

How to Use the Horse Feed Calculator

Our free horse feed calculator determines daily forage, grain, salt, mineral supplement, and water requirements based on your horse's body weight and activity level. Enter the horse's weight in pounds and select the activity level that best describes their workload. The calculator instantly displays all daily nutritional requirements, including the forage-to-total-feed ratio. Results update in real time as you adjust inputs.

Proper nutrition is the foundation of equine health and performance. Feeding too little forage can lead to digestive issues including colic and gastric ulcers. Overfeeding grain can cause laminitis, a painful and potentially life-threatening hoof condition. This calculator provides science-based guidelines that you can use as a starting point, then fine-tune with your equine veterinarian or nutritionist.

Understanding Equine Nutrition

Horses are hindgut fermenters evolved to eat fibrous plant material continuously throughout the day. The equine digestive system is designed to process a nearly constant stream of forage — going more than 4-6 hours without eating can lead to excess stomach acid production and increase the risk of gastric ulcers. This is why forage (hay and/or pasture) should always form the foundation of any horse's diet.

Forage: The Foundation

The National Research Council recommends a minimum of 1.5% of body weight in forage per day, with 2% or more being ideal for most horses. For a 1,000-pound horse, that translates to 15-20 pounds of hay daily. Quality matters as much as quantity — good grass hay provides 800-900 calories per pound, while alfalfa provides 1,000-1,100 calories per pound. A hay analysis from your local extension service helps you understand exactly what your forage provides.

When to Add Grain

Horses at maintenance or in light work often do not need grain at all if they receive adequate quality forage and a ration balancer or vitamin/mineral supplement. Grain becomes necessary when caloric demands from moderate to heavy exercise exceed what forage alone provides. The calculator estimates grain needs based on activity level, starting at 0% of body weight for maintenance and increasing to 1.2% for intense work.

Supplements, Salt, and Water

All horses need supplemental salt (sodium chloride) because forage and grain do not provide enough. A 1,000-pound horse needs approximately 1-2 ounces per day at rest. Mineral supplements fill gaps that forage and grain may not cover, particularly selenium, copper, zinc, and vitamins A, D, and E. Water requirements range from 5 to 10+ gallons per day and increase dramatically with exercise and hot weather.

Frequently Asked Questions

How much hay should a horse eat per day?

A horse should eat 1.5% to 2% of its body weight in forage per day. For a 1,000-pound horse, that is 15-20 pounds of hay daily. Forage should make up at least 50% of the total diet.

When does a horse need grain in addition to hay?

Horses at maintenance generally do not need grain with adequate quality hay and supplements. Grain becomes necessary at moderate or higher work levels when energy demands exceed what forage provides.

How much water does a horse need per day?

An average 1,000-pound horse drinks 5-10 gallons per day at rest. Working horses may need 15-20 gallons daily in summer. Provide 0.5-1 gallon per 100 pounds of body weight.

Does my horse need a salt block or loose salt?

Yes, all horses need supplemental salt. A 1,000-pound horse needs 1-2 ounces daily. Loose salt is preferred because horses may not lick blocks enough to meet needs.

What is the forage-to-grain ratio for horses?

At maintenance: nearly 100% forage. Light work: 80-85% forage. Moderate work: 70-75% forage. Heavy work: 60-65% forage. Forage should never drop below 50% of total intake.