Needle size finder for sewing thread

Pick your thread size and fabric weight to see the recommended needle size in Nm (metric) and Singer numbers.

Thread size Fabric

Estimates only. These results are for planning and guidance. Please re-check against your own samples and machine settings before ordering or production.

Why needle size matters

The needle eye and groove must be large enough for the thread to pass freely. A needle that is too small causes thread fraying, skipped stitches and breaks. A needle that is too large leaves visible holes and can weaken fine fabrics. Within the recommended range, use the smaller needle for light fabrics and the larger one for heavy fabrics.

See the full PolyCore and spun polyester ranges, or plan your order with the thread consumption calculator.

Size	Avg. strength (cN)	(kgf)	Recommended needle
Tex 18	910	0.93	Nm 65–75Singer 9–11
Tex 27	1,420	1.45	Nm 75–90Singer 11–14
Tex 34	1,780	1.82	Nm 80–90Singer 12–14
Tex 40	2,035	2.08	Nm 90–100Singer 14–16
Tex 60	3,170	3.23	Nm 100–120Singer 16–19
Tex 80	4,115	4.20	Nm 110–120Singer 18–19
Tex 90	4,400	4.49	Nm 110–130Singer 18–21
Tex 105	4,825	4.92	Nm 120–130Singer 19–21
Tex 120	6,110	6.23	Nm 120–140Singer 19–22
Tex 135	7,185	7.33	Nm 130–140Singer 21–22

Size	Approx. Tex	Avg. strength (cN)	(kgf)	Recommended needle
60/2	20	750	0.76	Nm 65–75Singer 9–11
50/2	24	890	0.91	Nm 70–80Singer 10–12
40/2	30	1,165	1.19	Nm 75–90Singer 11–14
34/2	35	1,430	1.46	Nm 80–90Singer 12–14
50/3	35	1,430	1.46	Nm 80–90Singer 12–14
30/2	40	1,695	1.73	Nm 90–100Singer 14–16
20/2	60	2,210	2.25	Nm 100–120Singer 16–19
20/3	90	3,625	3.70	Nm 110–130Singer 18–21