Das 4-8-Ziegen-Problem: Wie viel Kaschmir steckt in einem Pullover?

How many goats does it take to make one cashmere sweater? The answer often given is between four and eight goats, but that number needs some explanation. It does not mean that every goat produces the same amount of cashmere, or that every sweater requires exactly the same amount of fibre. The final number depends on the size of the sweater, the amount of cashmere collected from each goat, the quality of the fibre and how much material is lost during processing.

Cashmere comes from the fine undercoat of certain goats. During the spring moulting season, herders comb or collect this undercoat, which is then separated from the coarser outer hair. The raw material is not yet ready to become clothing. It must be cleaned, dehaired, spun into yarn and knitted or woven into a finished garment.

The United Nations Convention to Combat Desertification has stated that it takes approximately four to eight cashmere goats to produce enough fibre for one cashmere sweater. This estimate is widely used because an individual goat generally produces only a limited amount of usable fine fibre each year.

The important word in that estimate is “usable.” A goat may produce several hundred grams of raw fibre, but not all of it is fine cashmere. Some of the collected material consists of coarse guard hair, dirt and other unwanted material. The dehairing process removes much of this, leaving a smaller amount of fine cashmere. For example, if a goat produces 300 grams of raw fibre and only 40% of that material becomes usable cashmere, the final amount is:

300 grams × 40% = 120 grams of cashmere.

If a sweater requires 400 grams of finished cashmere yarn, it would take:

400 grams ÷ 120 grams = 3.3 goats.

That calculation would suggest that four goats could provide the fibre for the sweater, assuming the yield is relatively high and processing losses are limited. However, if the same goat produces only 200 grams of raw fibre and the usable proportion is 30%, the result changes:

200 grams × 30% = 60 grams of usable cashmere.

A 400-gram sweater would then require:

400 grams ÷ 60 grams = 6.7 goats.

That is where the estimate of four to eight goats comes from. Different goats produce different quantities of fibre, and the percentage of fine cashmere can vary considerably. The weight of the sweater also matters. A lightweight cashmere sweater might require around 250 to 300 grams of yarn, while a larger or heavier sweater could require 400 to 500 grams or more. A simple 300-gram sweater and a 500-gram sweater cannot be expected to use the same number of goats. Using a hypothetical yield of 75 grams of usable cashmere per goat, a 300-gram sweater would require:

300 grams ÷ 75 grams = 4 goats.

A 500-gram sweater would require:

500 grams ÷ 75 grams = 6.7 goats.

That means the same fibre yield could require four goats for a lighter sweater and seven goats for a heavier one. The calculation becomes even more complicated because raw cashmere and finished yarn are not the same thing. Fibre can be lost during sorting, washing, dehairing, spinning and other manufacturing stages. If a production process loses 15% of the usable fibre, a sweater requiring 400 grams of finished yarn would need:

400 grams ÷ 0.85 = approximately 471 grams of usable fibre before that loss.

If each goat provides 75 grams of usable fibre, the calculation becomes:

471 grams ÷ 75 grams = approximately 6.3 goats.

In that example, seven goats would be needed rather than six.

These figures are examples rather than a universal production standard. Actual cashmere yields vary depending on the goat's breed, age, sex, health, nutrition, climate and the way the fibre is collected. Fibre diameter also matters. Finer cashmere is generally more valuable for soft luxury garments, but the amount of fine fibre available from an animal is not necessarily the same as its total raw fleece weight.

Mongolia is one of the world's major cashmere-producing countries, and its national herd contains tens of millions of goats. According to Mongolia's livestock statistics, the country had approximately 22.9 million goats in 2024. That number represents the size of the animal population, not the amount of cashmere produced. To calculate fibre production, the number of goats must be combined with the average yield per animal and the percentage of fibre that can actually be recovered and processed.

The difference between the number of goats and the amount of usable cashmere is important. Two herds with the same number of goats could produce different amounts of fibre if the animals have different average yields or if the fibre quality and processing methods differ. So, how much cashmere goes into one sweater?

The commonly cited estimate is four to eight goats per sweater. A lighter sweater made from relatively high-yield fibre may fall near the lower end of that range, while a heavier sweater, lower-yield animals or greater processing losses may push the figure toward the higher end.

The number is therefore not a fixed rule. It is a calculation based on three main measurements: how much raw fibre a goat produces, how much of that fibre becomes usable cashmere and how much cashmere yarn is needed for the finished sweater.

A sweater may look like a single item of clothing, but its fibre requirements begin with several animals, a seasonal harvesting process and multiple stages of cleaning and manufacturing before the finished garment exists.