At a glance
| Volume | U-100, 1 mL mark | U-100, 0.3 mL mark | U-40, 1 mL mark |
|---|---|---|---|
| 0.02 mL | 2 | 2 | 0.8 |
| 0.05 mL | 5 | 5 | 2 |
| 0.1 mL | 10 | 10 | 4 |
| 0.15 mL | 15 | 15 | 6 |
| 0.2 mL | 20 | 20 | 8 |
| 0.25 mL | 25 | 25 | 10 |
| 0.3 mL | 30 | 30 | 12 |
Arithmetic at the concentrations shown. The concentration on your own label is the one that counts; enter it in the calculator.
Why the marks mean volume
The 0.3 mL syringe exists for small insulin doses, and its scale is the same U-100 scale as the larger sizes: 100 units per millilitre, so 0.3 mL is 30 units and the barrel stops there. What changes is the spacing. Thirty units spread along the same length of barrel that carries 100 units on the 1 mL size makes each unit more than three times as far apart, and many brands mark half units. That is why a 5-unit or 7.5-unit draw is easier to read on this syringe, and why the calculator can show half units on it. The trade is capacity: a 0.5 mL Zepbound vial does not fit, and neither does the 0.6 mL multi-dose withdrawal. On a U-40 syringe the same 0.3 mL is the 12 mark, because that scale has 40 marks per millilitre.
The mistake to watch for. A 0.3 mL syringe drawn to its top is 30 units of volume. It is not "a full dose" of anything unless the arithmetic for your vial happens to give 0.3 mL. Read the label, then the mark.