Wool Fleece Clean Yield Calculator (Grease Weight, Skirting, Micron & Yarn)

How it works

clean = grease × (1 − skirting) × scouring yield (fine 45–58%, medium 55–68%, long 65–75%, coarse 65–80%) · value = clean kg × clean price (set by micron) · yarn kg ≈ clean × 0.9 · metres = yarn kg × metres per kg (worsted ≈ 1,900; fingering ≈ 3,600)

Wool is bought and valued clean, so the weight that comes off the sheep is only the start: skirting removes the soiled edges, and scouring washes out lanolin, sweat salts and dirt that make up a third to a half of a fine fleece and a quarter of a coarse one. Price is then almost entirely a function of fibre diameter, with a steep premium for wool fine enough to wear against the skin, which is why a lightweight Merino clip can be worth more than a heavy longwool one. For a hand-spinner the same arithmetic runs through to metres of yarn, and a single medium fleece comfortably becomes a sweater and a hat.

Worked example

Twelve medium-wool ewes at 3.2 kg of grease fleece lose 12% to skirting and yield 62% on scouring, giving about 1.75 kg of clean wool each — 55% of the shorn weight — and 21 kg for the clip. At 26 µm and around $5 a clean kilo the clip is worth roughly $105, less than the shearing bill; sold to hand-spinners it fares far better. One fleece spins to about 1.57 kg of worsted yarn — roughly 3,000 m, enough for two or three sweaters or nineteen hats.

Frequently asked questions