Thread count
Also searched as: TC, threads per inch, ends and picks, EPI, PPI, ends per inch, picks per inch, fabric count, sett, thread density
Thread count is the number of warp ends plus weft picks in one square inch of woven fabric, most often quoted for bed sheets.
In detail
Weavers measure density separately in each direction: ends per inch or centimeter in the warp and picks per inch or centimeter in the weft. Thread count adds the two per square inch. Density interacts with yarn count: finer yarns allow more threads in the same space, while coarse yarns at high density would jam. Laboratories count threads with a pick glass or by raveling, on conditioned fabric away from the selvedge.
The science and numbers
Warp and weft densities, together with yarn linear density, determine cover: the proportion of fabric area occupied by yarn. Two fabrics with the same density can differ in cover if one uses coarser yarn. Density also governs crimp, air permeability and tear behavior; tightly set fabrics resist abrasion but can tear more easily because yarns cannot bunch to share load. Published studies commonly report construction in these terms; for example, one comparison of plain, twill and satin fabrics used warp densities of 90 to 100 ends per inch and weft densities of 50 to 60 picks per inch. Standard test methods specify counting direction, specimen location and how many counts to average. Mass per unit area can be estimated from densities, yarn tex values and crimp.
A practical example
A percale sample shows 110 ends and 90 picks per inch, a thread count of 200. A competing label claims 400 for a fabric with a similar hand. Under magnification the second fabric shows about 100 ends and 100 picks, but each yarn is two-ply. The 400 figure comes from counting plies, not yarns. The two fabrics are closer in construction than their labels suggest.
What to distinguish
A higher thread count is not a quality guarantee. Counting each ply of a plied yarn as a separate thread can double or triple the number without adding any more yarns, which can mislead a buyer comparing labels. Ask for ends and picks per inch, yarn count and ply. Fiber quality, finishing, weave and fabric weight matter as much as density.
Origins and history
Recording ends per unit width is intrinsic to weaving, since the warp must be set through a reed with a fixed number of dents per inch. The single combined thread-count number became a retail marketing figure for household textiles, and disputes over how plied yarns should be counted followed. This edition could not verify the current text of any regulator's guidance, so readers should consult the relevant authority directly.
Related terms
Sources & further reading
- CottonWorks: Weaving basics
- Heliyon: Mechanical properties of woven fabrics from 50/50 cotton-Tencel siro yarn (Afroz and Islam, 2021)
Technical references reviewed 2026-09-22. Examples are illustrative. Industry organizations and manufacturers describe their own fields; their references are not independent product endorsements. Figures are approximate and depend on the stated test conditions.