Horse Feed Calculator

At Light activity level (trail riding, pleasure riding), this calculator assumes the horse's energy needs are fully met by hay alone, so Grain per Day comes out to exactly zero regardless of Horse Weight or Body Condition Score -- grain only enters the ration starting at Moderate activity and above, scaling up to 1% of body weight at Very Heavy work like racing.

Body Condition Score follows the Henneke 1-9 scale, where 5 is ideal; scores above 5 indicate a horse carrying more body condition than needed, so this calculator reduces Hay per Day by up to 3% per point above 5 to avoid over-feeding an already well-conditioned horse, while scores below 5 increase hay by up to 4% per point to help an underweight horse regain condition.

Activity Level sets both the hay percentage (from 1.5% of body weight at Light work up to 2.25% at Very Heavy work) and the grain percentage (from 0% at Light up to 1% at Very Heavy), since harder-working horses burn more calories and need more concentrated energy from grain on top of increased hay intake.

Digestible Energy multiplies Hay per Day by 0.9 Mcal per pound and Grain per Day by 1.5 Mcal per pound, then sums the two, reflecting that grain concentrates typically carry more digestible energy per pound than forage -- this total is a rough energy estimate, not a substitute for a full nutritional analysis of your specific hay and grain.

It doesn't account for pasture grazing that could supplement or replace some hay, individual metabolic differences between horses, increased needs during pregnancy or lactation, seasonal changes in water intake and forage quality, or any veterinary- prescribed special diet for a horse with a health condition -- consult an equine nutritionist or veterinarian for a horse with unusual needs.