Thread Measurement
The thread as a unit: the old British yarn ladder
Thread is a confusing word in textiles, because alongside its everyday meaning it survives as an old British unit of yarn length. The honest record is not perfectly tidy: some sources give one thread as 54 inches (1.37 m), others as 55 inches, and this page presents the British standard ladder at 55 inches while flagging the disagreement openly — one thread equals 55 inches (139.7 cm); 80 threads make a skein or rap (120 yards); 7 skeins make a hank (840 yards); and 18 hanks make a spindle (15,120 yards, or 13.83 km). The page also separates the unit from thread count, the fabric measure it is most often confused with.
The hank at the top of this ladder is still the basis of the cotton count system. The Apparel Search Yarn & Spinning Guide explains how yarn is made and measured today, and its yarn count systems guide converts between Ne, Nm, tex and denier with worked examples.
OK, just to be clear Apparel Search is not a fan of the word "Thread" as a unit of measure. However, the British have been here before we arrived... Thread has a different meaning in regard to textiles so this is a bit confusing.
We have read that the following definition, "Thread is a cotton yarn measure, equal to 54 inches (1.37m)." However, we have also found some where else that 1 thread is 55 inches. So which is it? Is it 54 inches or 55 inches?
Please use the following at your own risk...
British standard yarn measures:
- 1 thread = 55 in or 139.7 cm
- 1 skein or rap = 80 threads (120 yd or 110 m)
- 1 hank = 7 skeins (840 yd or 770 m)
- 1 spindle = 18 hanks (15,120 yd or 13.83 km)
Note: this is different than thread count. Thread count or threads per inch (TPI) is a measure of the coarseness or fineness of fabric. It is measured by counting the number of threads contained in one square inch of fabric or one square centimeter, including both the length (warp) and width (weft) threads.
You may want to visit the following websites to learn more about thread:
Thread Weights & Measures (Superior Threads)
Thread Numbering (Coats)
A Ladder Built for the Mill
The British yarn ladder climbs by handfuls a working mill could actually handle: a thread was one turn of the reel (the circumference of a warp beam, in the related definition), threads bundled into skeins, skeins into hanks, and hanks into spindles large enough to trade. Each step multiplies cleanly — 80, then 7, then 18 — so a clerk could convert a delivery note in his head. The same 840-yard hank anchors the cotton count system, which is why this antique ladder still matters: the counts printed on modern yarn specifications are standing on these definitions, even when the words thread, rap and spindle themselves have retired from daily use.
Handling a Unit the Sources Argue About
The 54-versus-55-inch discrepancy is a useful lesson in historical metrology: old units were set by physical reels and local practice before they were set by committees, so honest references can disagree by the width of the apparatus. Where the difference matters — converting an antique specification, say — the safe practice is to state which value you used, keep conversions consistent within a document, and remember that a one-inch difference in a 55-inch unit is under two percent, smaller than the variation the yarns themselves carried. For most modern purposes thread count, not the thread unit, is the number a fabric buyer actually needs, and this section gives thread count its own page for exactly that reason.
Common Questions
How long is one thread as a unit of measure?
In the British standard yarn measures presented here, one thread equals 55 inches (139.7 cm); some sources give 54 inches, and the disagreement is noted on the page.
How do threads build into skeins, hanks and spindles?
80 threads make one skein or rap (120 yards), 7 skeins make one hank (840 yards), and 18 hanks make one spindle (15,120 yards).
Is the thread unit the same as thread count?
No. The thread is an old unit of yarn length; thread count is a fabric measure — the warp plus weft threads in one square inch of woven fabric.