IV Cannula Sizes and Colour Codes: 14G to 26G Chart
The colour of an IV cannula's hub tells you its gauge at a glance. This chart gives each gauge's colour, outer diameter, typical flow rate and common use.
What are the IV cannula colour codes?
IV cannula colours follow ISO 10555-5: 14G orange, 16G grey, 17G white, 18G green, 20G pink, 22G blue, 24G yellow and 26G violet. The smaller the gauge number, the wider the cannula and the faster the flow: a 14G runs more than ten times faster than a 24G.
IV cannula gauge chart
| Gauge | Colour | Outer diameter | Typical flow | Common use |
|---|---|---|---|---|
| 14G | Orange | 2.1 mm | ~240–330 ml/min | Trauma, rapid fluid or blood replacement |
| 16G | Grey | 1.7 mm | ~180–240 ml/min | Major surgery, rapid transfusion |
| 17G | White | 1.5 mm | ~125–140 ml/min | Rapid infusion where 16G is too large |
| 18G | Green | 1.3 mm | ~90–100 ml/min | Blood transfusion, surgery, contrast |
| 20G | Pink | 1.1 mm | ~55–65 ml/min | Routine adult infusions and medicines |
| 22G | Blue | 0.9 mm | ~33–36 ml/min | Small or fragile veins, elderly, children |
| 24G | Yellow | 0.7 mm | ~20–22 ml/min | Paediatrics, neonates, very small veins |
| 26G | Violet | 0.6 mm | ~13–15 ml/min | Neonates |
Flow rates are typical gravity values for water through a short peripheral cannula; the rate on the manufacturer's pack is the one to use.
Hypodermic needle colours are a different system
Needles follow ISO 6009, so the same colour means a different gauge on a needle and on a cannula: pink is 18G on a needle but 20G on a cannula.
| Needle gauge | Colour (ISO 6009) |
|---|---|
| 18G | Pink |
| 19G | Cream |
| 20G | Yellow |
| 21G | Deep green |
| 22G | Black |
| 23G | Deep blue |
| 24G | Medium purple |
| 25G | Orange |
| 26G | Brown |
| 27G | Medium grey |
We manufacture IV cannula from 14G to 26G, colour-coded to ISO 10555-5, with injection port and wings.
Frequently asked questions
What colour is an 18G cannula?
Green. Under ISO 10555-5 an 18G IV cannula has a green hub; it is the usual size for blood transfusion and surgery in adults.
Which cannula size is used for blood transfusion?
Usually 18G (green) in adults, or 16G (grey) when blood must be given fast. Smaller gauges can be used when veins are small, following local protocol.
What is the flow rate of a 22G cannula?
Typically about 33–36 ml per minute under gravity. Check the flow rate printed on the pack, because it varies with the cannula's length and design.
Is the cannula colour code the same as the needle colour code?
No. Cannulas follow ISO 10555-5 and needles follow ISO 6009, so the colours do not match: pink is a 20G cannula but an 18G needle.
Which IV cannula sizes should a hospital order?
Most adult wards use 18G, 20G and 22G; theatres and emergency departments add 14G and 16G; paediatric and neonatal units need 22G, 24G and 26G. Order by gauge, with and without injection port, as separate tender lines.
Buyer guides on this topic
- Safety IV Cannula with Passive Needle Guard: ISO 10555-5 Specifications, Gauge Sizing & Sourcing from India
- Pediatric & Neonatal IV Cannula (24G & 26G) Sourcing: Flow Dynamics, Flashback Chambers, and UAE MOHAP Guidelines
- IV Cannula Manufacturer in India vs China: The Comparison Tanzanian Importers Actually Run
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