This is the lookup table for cord and rope diameters on our product pages. Each size is given in millimetres, with the exact inch conversion (mm ÷ 25.4), the fractional-inch name the trade uses, and the products that come in it. For why sizes go wrong and how to measure, read the cord size guide.
Diameter chart
A product is listed at a size when that size falls inside the range its product page states, or is one of the sizes it lists. Some pages give an approximate range (“roughly” or “approx.”), so confirm the exact diameter in your enquiry. Several lines also make in-between diameters to order; the product table below says which.
Sizes by product
| Product | Sizes as stated |
|---|---|
| Waxed cotton cord | 0.5, 0.8, 1, 1.5 and 2 mm; intermediate diameters to order |
| Elastic thread | Rubber core diameters 0.5 to 15 mm; 0.5, 0.7 and 1 mm are the standard fine gauges |
| Rattail cord | 1, 2 and 3 mm |
| Bakers twine | Approx. 1 to 2 mm depending on ply count |
| Cotton crochet and macrame yarn | Roughly 1 to 5 mm finished diameter |
| Round elastic cord | 1 to 3 mm as standard; heavier diameters on request |
| Macrame cord | 1.5 to 10 mm |
| Danish cord | 2 to 3 mm |
| Paracord | 2, 3, 4, 5 and 6 mm, including 550-type |
| Piping cord | Roughly 2 to 8 mm; in-between diameters to order |
| Dori and drawcord (round) | 2 to 12 mm round; flat braid 5 to 20 mm wide |
| Tufting yarn | Roughly 2 to 6 mm finished diameter |
| Round shoelaces | Round 2 to 8 mm; flat 5 to 15 mm wide |
| Jute rope | 2 to 32 mm |
| Crochet cord | 3 and 5 mm; other gauges braided to order |
| Jute garden twine | Approx. 3 to 5 mm depending on yarn count |
| Cotton rope | Roughly 3 to 30 mm; other diameters to order |
| Bungee and shock cord | 3 to 12 mm |
| T-shirt yarn | 7 to 9 mm stretch width |
| Cloth drying rope | Diameter to your specification |
| Curtain tie backs | Custom rope diameters on request |
Candle wick is specified by ply count, matched to vessel diameter and wax type, not by millimetre. See the candle wick page.
Reading inch sizes
Cord is made to a metric diameter. The inch name is a label, not a tolerance. 3 mm is sold as 1/8″ (0.125 in) but measures 0.118 in, and 10 mm is sold as 3/8″ (0.375 in) but measures 0.394 in. If you are converting an inch order, use the exact column and pick the nearest millimetre size, then confirm it with a sample.
Diameter alone does not define a cord. Construction (twisted or braided, ply or carrier count), fibre and put-up change weight, feel and price at the same size. The cord specification guide lists the six lines to send, and the wholesale ordering guide covers minimums and samples.
Questions
What is 1/4 inch cord in mm?
1/4″ is 6.35 mm, sold as 6 mm. Macrame cord, paracord, jute rope, cotton rope, bungee cord, piping cord, drawcord, tufting yarn and round shoelaces are all listed at 6 mm.
What is 3 mm in inches?
3 mm is 0.118 in, sold as 1/8″.
What is the thickest rope listed?
Jute rope, up to 32 mm (about 1-1/4″). Cotton rope runs to roughly 30 mm.
What is the finest cord listed?
Waxed cotton cord at 0.5 mm, and elastic thread with a 0.5 mm rubber core.