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General product information only, not medical advice. Which needle is used for a given person or donation is decided by trained staff under their facility’s protocol and the product’s labelling.
The size of a blood-collection needle is printed on its label as a gauge (G) and a length. BD’s Vacutainer Eclipse blood-collection needle, for example, is listed at 21 G and 1 1/4 in. This page puts the manufacturer-listed sizes in one table, shows how to read them, and explains what the ISO 6009 colour code does and does not tell you.
Blood draw needle size chart (manufacturer-listed sizes)
Sizes below are copied from BD product pages (checked 2026-11-01). The first row is a blood-collection needle; the remaining rows are BD’s general-purpose hypodermic needles and are shown only so you can see how one manufacturer pairs gauge, length and hub colour. They are not blood-draw recommendations.
| Product (BD) | Gauge | Length | Hub colour as listed |
|---|---|---|---|
| Vacutainer Eclipse blood collection needle (SKU 368607) | 21 G | 1 1/4 in | Not stated on the page |
| Eclipse hypodermic needle | 18 G | 1 1/2 in | Pink |
| Eclipse hypodermic needle | 21 G | 1 in | Green |
| Eclipse hypodermic needle | 22 G | 1 in | Black |
| Eclipse hypodermic needle | 23 G | 1 in | Blue |
| Eclipse hypodermic needle | 25 G | 1 in | Orange |
| Eclipse hypodermic needle | 27 G | 1/2 in | Gray |
| Eclipse hypodermic needle | 30 G | 1/2 in | Yellow |
Check your product’s labelling: the pack and the needle’s own markings are the authority for its size, not this table.
How to read the chart
Gauge is a number, and a higher number means a thinner needle: 30 G is much finer than 18 G. The pattern is explained in why a bigger gauge means a smaller needle, which also carries the gauge-to-millimetre chart, so it is not repeated here. Length is given separately, in inches on BD’s US listings.
The blood-collection product page also lists features that matter when you read a listing: a shielded needle with needlestick protection (a safety-engineered product), sterilisation by gamma irradiation, and single use. Pack data on the same page: 48 needles per shelfpack and 480 per case.
What gauge needle is used for a blood draw?
The manufacturer’s blood-collection needle in the table above is listed at 21 G and 1 1/4 in. The gauge used on a particular person is chosen by trained staff according to facility protocol and the product’s instructions, so this page does not tell you which to use. For a comparison of needle types used in venipuncture, see butterfly needle vs straight needle, and for the device itself, what a Vacutainer needle is.
What size needle for blood donation?
The same rule applies: the collecting organisation’s protocol and the labelling of the collection set determine the needle. Donation sets are specific products with their own labels, and the hypodermic sizes in the table are not donation needles.
Gauge, millimetres and colour: what ISO 6009 says
ISO 6009:2016 establishes a colour code for identifying single-use hypodermic needles of designated metric size, from 0.18 mm (34 G) to 3.4 mm (10 G), and applies to regular-walled, thin-walled, extra-thin-walled and ultra-thin-walled needles. According to ISO’s catalogue description, it is not applicable to pen needles.
The BD hypodermic rows above show one manufacturer’s pairing of gauge and hub colour (for example 21 G green and 22 G black); the BD blood-collection page does not state a hub colour at all. Colours here are attributed to BD, not to ISO. Standard: ISO 6009:2016.
Common mix-ups
- Hypodermic needle versus blood-collection needle. A 21 G hypodermic needle and a 21 G blood-collection needle share a gauge but are different products. See what a hypodermic needle is.
- Colour versus gauge. A hub colour is a visual cue; the printed size on the pack and needle is the reference.
- Gauge versus length. Two needles of the same gauge can differ in length, as the 18 G and 21 G rows show.
- Tube colours versus needle colours. Tube-stopper colours identify additives and are a separate system; see blood draw tube colors.
- Needle versus catheter. IV catheters use their own gauge guidance, covered in IV catheter gauge selection.
Reading a listing or SKU
The BD blood-collection listing shows the fields worth checking on any needle: gauge, length, safety feature, sterility, single-use status, and pack quantity. Where a listing leaves one blank, as BD’s does for hub colour, ask the manufacturer rather than assuming. The phlebotomy lab supply checklist shows where needles sit among related supplies.
FAQ
What size needle for blood donation?
Donation sets are specific products; the collecting organisation’s protocol and the set’s labelling determine the needle, and the hypodermic sizes in the table are not donation needles.
What size needle for drawing blood?
BD lists its Vacutainer Eclipse blood-collection needle at 21 G and 1 1/4 in. The size used in practice is set by trained staff following facility protocol and product labelling.
What gauge needle to draw blood?
The listed blood-collection needle is 21 G; the choice for any person rests with trained staff, not with a web page.
Is a higher gauge number a bigger needle?
No. A higher gauge number is a thinner needle.
Does the hub colour tell me the gauge?
ISO 6009 defines a colour code for single-use hypodermic needles, but the blood-collection needle on BD’s page states no hub colour, so read the printed gauge and length on the pack.
Are phlebotomy needle sizes the same as IV catheter sizes?
They are different devices with separate guidance.
Sources
- BD, BD Vacutainer Eclipse Blood Collection Needle, SKU 368607, checked 2026-11-01.
- BD, BD Eclipse Needle (hypodermic), checked 2026-11-01.
- ISO, ISO 6009:2016, Hypodermic needles for single use, colour coding for identification, catalogue description checked 2026-11-01.
