Syringe and Needle Size (Gauge) Guide

Needle size is expressed with the "gauge" (G) system. It can be confusing at first because the higher the number, the thinner the needle: 30G is much thinner than 21G.

Gauge, outer diameter and color table

Needle hub colors are coded according to the ISO 6009 standard. The values below are taken from Terumo's product information card for sterile single-use hypodermic needles.

As the table shows, 20G and 30G needles are both yellow, so color alone does not identify the size. Check gauge and mm together when ordering and using needles.

Syringe volume and tip type

Syringes come in volumes such as 1, 2, 5, 10 and 20 ml. The tip type (luer lock or luer slip) determines needle and set compatibility. Which size to use for which application depends on the procedure protocol and the clinician; this article covers sizing and purchasing.

Needle purchasing checklist

1. Have gauge and mm stated together.
2. Specify needle length in mm.
3. Check the bevel (regular or short); it is listed on the manufacturer's card.
4. Confirm luer lock / luer slip compatibility with your syringes.
5. Check the CE marking and notified body number on the packaging.
6. Where latex sensitivity matters, check that the product card states no natural rubber latex.
7. See the quantity per box and the expiry date in the quote.

Wholesale supply

Clinimate supplies syringes, needle tips, cannulas and sets wholesale to clinics, hospitals and laboratories. Share the gauge, length, volume and monthly quantity you need, and we will prepare a same-day quote with the right product and an equivalent alternative. Get a quote.