This article has not yet been professionally approved. The information is based on the sources listed below.
Ration calculation for horses: explained step by step
What you need for a ration calculation, how requirement and intake are compared and how to recognise a useful result and a good ration calculator.
The short answer
A ration calculation compares two sides: the horse's requirement based on weight, work and life stage, and the intake from all feeds 12. For each nutrient, the daily amount of each feed is multiplied by its content and added up. The result shows calculated gaps and surpluses. It is most accurate with weighed amounts and a hay analysis 3.
What a ration calculation is
A ration calculation answers a simple question with numbers: does the horse get what it needs from its entire feed, and not significantly more? The calculation method is well described in German-speaking countries and is based on the requirement recommendations of the GfE (German Society of Nutrition Physiology) 14.
It is not an examination of the horse. It calculates with what you enter and with reference values for a healthy horse of the selected group.
Step 1: Describe the horse
The requirement depends mainly on body weight, work and life stage 15. If no scales are available, a weight tape estimate provides a starting value. Body condition complements the weight, because it shows whether the current energy intake is appropriate 6.
- Weight or weight tape estimate
- Body condition (body condition score)
- Type and amount of work per week
- Life stage: maintenance, growth, pregnancy or lactation
Step 2: Determine the requirement
The requirement is made up of the maintenance requirement plus additions for work or life stage. The values are listed in requirement tables; for a calm 500 kg warmblood, the energy requirement at maintenance is around 55 MJ metabolisable energy per day 12. Flat-rate factors from the internet do not replace these tables.
Step 3: Record the intake
On the intake side, every feed is listed with its weighed daily amount: hay, pasture, concentrates, mineral feed and all supplements. Hay is the largest item and at the same time the most uncertain, because its mineral contents vary widely depending on location and growth 3. A representative hay sample from several bales makes the calculation considerably more accurate 7.
Step 4: Draw up the balance
For each nutrient, the daily amount of each feed is multiplied by its content and added up across all feeds. The total is compared with the requirement 2. It is important to use the same reference basis: lab values often refer to dry matter, while the amount fed refers to the as-fed basis.
| Calculation step | Value |
|---|---|
| Hay per day (as fed) | 10 kg |
| Dry matter according to lab report | 88% |
| Hay as dry matter | 10 × 0.88 = 8.8 kg |
| Calcium according to lab report | 4 g per kg dry matter |
| Calcium from hay per day | 8.8 × 4 = 35.2 g |
Freely chosen worked example for calcium from hay; not a real hay sample and not a requirement figure for a specific horse.
Step 5: Interpret the result
Values well below the requirement show a calculated gap, values well above it an oversupply. For additives, maximum contents also apply, which refer to the whole ration 8. The ratio of calcium to phosphorus is also part of the assessment 15.
How a gap is closed is a separate decision: via a different forage, a change to the ration or a targeted supplement 9.
How to recognise a good ration calculator
- It asks about the entire feed, not just the mineral feed.
- It shows which values are measured and which are estimated.
- It flags surpluses, not just gaps.
- The calculation is transparent and can be repeated with new hay values.
- It does not automatically recommend a particular product range 10.
Where the calculation ends
A ration calculation does not make a diagnosis. In the case of illness, ongoing medication, during growth or for pregnant and lactating mares, feeding should be managed with specialist support 10. In such situations, Equivora deliberately does not create an automatic mix; the calculation can still serve as a basis for discussion.
Key takeaways
Frequently asked questions
What do I need for a ration calculation?
The horse's weight or a weight tape estimate, body condition, work and life stage, plus the weighed daily amounts of all feeds with their contents. For the hay, a lab analysis is more accurate than a table value 36.
Can I calculate the ration without a hay analysis?
Yes, but then with table or regional values that may differ considerably from your hay 3. At Equivora, every estimated value is marked as such. Selenium and iodine remain open without a lab value; the mix then does not add them in a targeted way.
How often should I recalculate the ration?
With every new batch of hay, when weight, work or housing change, and when you add or remove a feed. A sample only represents the lot that was sampled 7.
Does a ration calculator replace feeding advice?
Not always. The calculation shows gaps and surpluses, but it does not examine a horse. In the case of illness, during growth or for pregnant mares, specialist support should be involved 10.
Sources & studies
The content is based on the references listed below. It does not replace individual veterinary or feeding advice.
Show list of sources (10)
- GfE (2014) – Empfehlungen zur Energie- und Nährstoffversorgung von PferdenSpecialist reference in German-speaking countries (GfE, German Society of Nutrition Physiology), Committee for Requirement Standards
- Bayerische Landesanstalt für Landwirtschaft (LfL): Gruber Tabelle zur PferdefütterungPractical reference table with requirement and feed values based on the GfE recommendations; the basis of many ration calculations in German-speaking countries. Chapter 9.3, Table 39: most common poisonous plants for horses with habitat, toxicity and risk level (after Kamphues et al. 2014)
- Möllmann F (2007): Analysen und Abschätzung des Mineralstoffgehaltes in Heuproben aus oberbayerischen Pferdehaltungsbetrieben. Diss. med. vet., LMU MünchenGrass hay samples from horse yards in Upper Bavaria; empirical database for the mineral contents (Ca, P, Mg etc.) of German grass hay, with wide variation by location, soil and cut. Open access.
- Kienzle, Pankratz & Zeyner (2023) – Kompendium zur Rationsberechnung für PferdeAuthor group Pferdewissen (Kienzle/Pankratz, LMU Munich; Zeyner, University of Halle-Wittenberg); self-published, Oberschleißheim, ISBN 978-3-00-075668-9. No link – self-published, not freely accessible.
- NRC – Nutrient Requirements of Horses, 6th ed.International reference for the nutrient requirements of horses (National Research Council)
- Henneke DR, Potter GD, Kreider JL, Yeates BF (1983): Relationship between condition score, physical measurements and body fat percentage in mares. Equine Veterinary Journal 15(4):371–372Original publication on the body condition score; bibliographically checked. Its application and limits are additionally supported by horse-specific specialist reviews.
- LUFA Nord-West: Probenahme Pferdefutter – Wie gehe ich korrekt vor?Laboratory instructions: representative samples from several bales and layers, identical labelling of sample and order. Checked online on 28 September 2026.
- Verordnung (EG) Nr. 1831/2003Feed additives – authorisation and use; “daily ration” based on 12% moisture (Art. 2(2)(f)), renewal of authorisation and automatic continuation (Art. 14(4)), general conditions of use (Annex IV: natural plus added amount; complementary feed, diluted as specified, at most at the level for complete feed). Link to the current EUR-Lex consolidated version (as of 27 March 2021).
- Coenen M, Vervuert I (2020): Pferdefütterung. Begründet von H. Meyer. 6., aktualisierte Aufl., Georg Thieme Verlag, Stuttgart. ISBN 978-3-13-241778-6Standard reference work on equine nutrition in German-speaking countries; Table 4.17 mineral recommendations (recommended supply and minimum requirement), Table 4.18 derived sweat volumes per work level and weight class, Table 4.19 electrolyte performance requirement per sweat volume (in addition to maintenance requirement)
- Go4Vet: Futterberatung fürs Pferd – Ablauf, Kosten & NutzenGuide from a veterinary platform: “Futterberater” (feed adviser) is not a protected professional title in Germany and Austria; advice is particularly useful for metabolic disorders (EMS, Cushing's), recurrent colic, during growth, for sport horses in intensive training and for older horses; a warning sign is free advice that only recommends a particular product range