How this horse feed calculator works

This calculator focuses on hay quantity, not a complete feed ration. Enter body weight, the percentage intended as hay on an as-fed basis, bale weight, and expected waste. It does not automatically add grain, supplements, or minerals, and it does not subtract a guessed amount of pasture. If your nutritionist specifies dry-matter intake, convert that plan to an appropriate as-fed quantity before using the purchase calculation.

A worked example

A 1,000-pound horse at an entered two-percent as-fed hay allowance gives 20 lb daily intake. If ten percent of purchased hay is lost, purchasing 20 ÷ 0.9 = 22.22 lb covers that intake. At 50 lb per bale, round up to one whole bale for the one-day example.

Waste means a share of purchases

A ten-percent loss means ninety percent of what you buy reaches the animal. Divide the required intake by 0.9 rather than simply adding ten percent to it. That distinction becomes meaningful over a winter or across several horses. Waste here includes your chosen combined allowance for loss; the calculator does not independently estimate feeder performance, spoilage, or storage damage. Use a measured farm record where available.

Bale weight and practical rounding

Enter the bale’s actual average weight rather than relying on its dimensions or a generic label. Total mass is divided by that weight, then rounded up once to obtain a whole-bale purchase quantity. Rounding each horse or each day separately would produce a different and often inflated order. If weights vary considerably, retain a practical reserve and plan storage without treating the arithmetic as an inventory guarantee.

Keep nutrition separate from inventory

Hay mass alone does not establish digestible energy, protein, minerals, or suitability. The entered percentage and as-fed basis must agree with the feeding plan. Pasture and other feeds are not automatically included. Discuss hay analysis and individual requirements with an equine nutritionist, particularly for health restrictions or demanding workloads. Printed calculations should include the input percentage, days, animal count, bale weight, and waste so the order can be reproduced.

Sources and review status

The source links and editorial check date are shown beside this explanation. They identify the reference used for the calculation, not an endorsement of this site. No veterinarian has reviewed this implementation. A change in source evidence should lead to a new check of the equation, input choices, and example.

Horse Feed Calculator