# Horse Feed Calculator Horse feed calculator by weight: figure out daily hay, grain, and total ration using NRC nutrition standards. Works for Nutrena, Purina, and any horse feed. ## What this calculates Dial in how much hay and grain your horse really needs. This horse feed calculator sizes the daily ration from body weight and workload using the NRC digestible energy equations that veterinary nutritionists rely on, then converts the grain amount to familiar 3-quart scoops. ## Inputs - **Horse's Body Weight** (lb) — min 100, max 2500 — Average adult horse weighs about 1,000 to 1,200 lb - **Workload** — options: Maintenance / Pasture pet, Light work (1-3 hrs/wk, trail or light riding), Moderate work (3-5 hrs/wk, ranch or lesson), Heavy work (4-5 hrs/wk intense, racing, eventing), Very heavy (racehorse in training, elite sport), Broodmare (late gestation), Broodmare (lactating) - **Hay Energy Density** (Mcal/lb) — min 0.7, max 1.2 — Average grass hay is ~0.85-0.95 Mcal/lb; alfalfa is ~1.0-1.1 - **Grain / Concentrate Energy Density** (Mcal/lb) — min 1, max 2 — Typical commercial horse feed (Nutrena, Purina) is ~1.3-1.6 Mcal/lb ## Outputs - **Daily Digestible Energy Required** — NRC Digestible Energy requirement for this workload - **Total Daily Feed Intake** — Approximately 2-2.5% of body weight in total feed - **Hay / Forage** — Forage should make up at least 50-60% of the ration - **Grain / Concentrate** — Balance of energy needs above what hay supplies - **Grain in Scoops** — formatted as text — Approximate scoops of grain to feed a horse per day (3-quart scoop) - **Monthly Hay Usage** — Total hay needed per month at this feeding rate - **Feeding Guide** — formatted as text — Practical feeding recommendation for this workload ## Details How much grain to feed a horse per day The backbone of any horse ration is forage (hay or pasture) at 1.5 to 2 percent of body weight on a dry matter basis. A 1,100 lb horse should eat roughly 16.5 to 22 lb of hay per day before any grain is added. Grain makes up the difference between the energy hay supplies and the energy the horse's workload demands. The NRC 2007 equation for maintenance digestible energy is: - DE (Mcal/day) = 0.0333 x body weight (kg) - Working horse DE = Maintenance DE x workload multiplier (1.2 light, 1.4 moderate, 1.6 heavy, 1.9 very heavy) - Late-gestation broodmare = 1.2 x maintenance - Lactating broodmare = 1.7 x maintenance Horse feed calculator by weight Start with the horse's body weight. Use a weight tape around the heart girth or the simple formula heart girth^2 x body length / 330 if you don't have a livestock scale. Most adult riding horses land between 900 and 1,300 lb. Once you know the weight, multiply by 2.0 to 2.5 percent to get total daily intake on a dry matter basis. That covers every bite the horse eats, including hay, grain, and treats. How many scoops of grain to feed a horse Most barns use a 3-quart plastic scoop, which holds roughly 3 lb of textured sweet feed or pellets. If the calculator says to feed 6 lb of grain per day, that is about 2 scoops, usually split into a morning and evening meal. Never feed more than 5 lb of grain in a single meal, as large starch loads cause colic and laminitis risk. Purina and Nutrena horse feed This calculator works with any brand. For a Nutrena horse feed calculator approach, use the Mcal/lb figure from the bag tag: Nutrena SafeChoice Original is about 1.42 Mcal/lb, Nutrena ProForce Fuel is 1.55 Mcal/lb, and Nutrena Empower Boost is 1.68 Mcal/lb. The Purina horse feed calculator inputs look similar: Purina Strategy Professional Formula GX is ~1.38 Mcal/lb, Purina Ultium Competition is ~1.65 Mcal/lb, and Purina Senior is ~1.35 Mcal/lb. If you want to run a Nutrena horse feed comparison or compare to a Purina line, plug in each product's Mcal/lb in turn and see how the grain amount shifts. Cheaper high-fiber feeds tend to be lower energy, so you end up feeding more pounds to hit the same DE target. Looking for Nutrena horse feed coupons or information about Nutrena horse feed ingredients? Those come directly from Nutrena's website and your local feed dealer, not a calculator. Use this tool to figure out how much of any brand you actually need, which is the real way to save money on horse feed. How much to feed a horse per month Multiply the daily hay amount by 30. A 1,100 lb horse in moderate work on 16 lb of hay per day will burn through about 480 lb, or roughly 10 to 11 small square bales, per month. Grain usage is easier: a 50 lb bag of concentrate at 4 lb per day lasts 12.5 days, so a horse in moderate work needs about 2.5 bags per month. ## Frequently Asked Questions **Q: How much grain to feed a horse per day?** A: A healthy adult horse in moderate work typically needs 4 to 7 lb of grain per day, split into two or three meals. A 1,100 lb horse at moderate work targeting 23 Mcal of digestible energy on hay at 0.9 Mcal/lb and grain at 1.45 Mcal/lb will eat about 19 lb of hay and 4 lb of grain daily. Horses at maintenance or light work often need no grain at all, and hard-working performance horses may need 8 to 12 lb per day. **Q: How many scoops of grain to feed a horse?** A: A standard 3-quart plastic feed scoop holds about 3 lb of most textured or pelleted horse feeds. If this calculator shows 6 lb of grain per day, that is 2 scoops, typically split into a morning and evening feeding. Always weigh your specific grain on a kitchen scale once per bag, because density varies significantly between pelleted feeds, textured sweet feeds, and extruded products. **Q: How much hay do I need to feed a horse per month?** A: Most adult horses eat 15 to 25 lb of hay per day, so monthly hay use runs 450 to 750 lb per horse. A 1,100 lb pleasure horse on 16 lb per day burns through about 480 lb per month, which is roughly 10 small square bales (at 50 lb/bale) or one half of a typical 1,000 lb round bale. Buy hay in bulk after the first cutting to get the best price per ton. **Q: Does this tool work as a Purina or Nutrena horse feed calculator?** A: Yes. Enter the Mcal/lb value from your bag. Nutrena SafeChoice Original is about 1.42 Mcal/lb, Purina Strategy GX is about 1.38 Mcal/lb, Purina Ultium Competition is about 1.65 Mcal/lb, and Nutrena ProForce Fuel is about 1.55 Mcal/lb. The calculator will size the grain amount based on whichever product you choose. For a full Nutrena horse feed comparison, run the numbers for each product with the same horse weight and workload. **Q: How do I weigh my horse without a scale?** A: Use a weight tape around the heart girth just behind the elbow, or calculate it from measurements using the formula: body weight (lb) = (heart girth in inches)^2 x body length (point of shoulder to point of buttock in inches) / 330. Weight tapes are accurate within about 5 percent for average-build horses but may under-read heavily muscled stock horses and over-read very fit racehorses. **Q: Should I feed alfalfa or grass hay?** A: Grass hay (timothy, orchard, brome) at 0.85-0.95 Mcal/lb suits most horses at maintenance or light work. Alfalfa at 1.0-1.1 Mcal/lb provides more energy, protein, and calcium, which is useful for hard-working horses, lactating mares, and young growing stock. A 50/50 mix is popular because it balances energy and palatability without overloading on protein. Always adjust the grain portion down when switching to alfalfa to avoid excess calories. --- Source: https://vastcalc.com/calculators/health/horse-feed Category: Health & Fitness Last updated: 2026-04-08