Below is a needle gauge chart showing the sizes of needles used for the Evacuated Tube System, Syringe Method, and the Butterfly Needle when performing venipuncture.
Tables showing needle sizes for blood draws
The evacuated tube method is used for good and healthy veins found in the antecubital fossa area.
| Needle Gauge | Color Code | Length | Uses | Age Range |
| 21 | Green | 1 inch 1 1/4 inch 1 1/2 inch | Use for large veins that are good and healthy | Some adolescents, teenagers, adults |
| 22 | Black | 1 inch 1 1/4 inch 1 1/2 inch | Use for medium sized veins that are good and healthy | Some adolescents, teenagers, adults |
| 23 | Blue | 1 inch 1 1/4 inch 1 1/2 inch | Use for smaller and thinner veins that are good and healthy | School age, adolescents, adults |
Click here to find out more about the evacuated tube method and its uses.
The syringe is good for veins that the evacuated tube system fails to hit or draw blood from. It can do deep veins as well as difficult veins.
| Needle Gauge | Color Code | Length | Uses | Age Range |
| 21 | Green | 1 inch 1 1/4 inch 1 1/2 inch | Use for large veins at the back of hand, forearm, antecubital fossa area | Some adolescents, adults, elderly |
| 22 | Black | 1 inch 1 1/4 inch 1 1/2 inch | Use for medium sized veins at the back of the hand, forearm, antecubital fossa area | School age, adolescents, adults, elderly |
| 23 | Blue | 1 inch 1 1/4 inch 1 1/2 inch | Use for small, thin, rolling, fragile veins, other difficult veins | Infants, babies, children, adolescents, adults, elderly |
Click here to read more about the advantages and disadvantages of the syringe method.
The butterfly is good for infants, babies, children, those who fear needles, the elderly, and difficult stick/veins.
| Needle Gauge | Color Code | Length | Uses | Age Range |
| 21 | Green | 3/4 inch | Large superficial veins (back of hand, forearm antecubital fossa) | Adolescents, adults, elderly |
| 22 | Black | 3/4 inch | Medium superficial veins (back of hand, forearm antecubital fossa) | School age, adolescents, adults, elderly |
| 23 | Blue | 3/4 inch | Small superficial veins (back of hand, forearm antecubital fossa) | Infants, babies, children, adolescents, adults, elderly |
Click here to find out the instances when you should use a butterfly needle.