Horse Feed Calculator
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.
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.