Units to mL calculator for U-100 syringes
| Markings | Volume | Fits within capacity |
|---|---|---|
| 5 units | 0.05 mL | 0.3, 0.5 or 1 mL |
| 10 units | 0.10 mL | 0.3, 0.5 or 1 mL |
| 15 units | 0.15 mL | 0.3, 0.5 or 1 mL |
| 20 units | 0.20 mL | 0.3, 0.5 or 1 mL |
| 25 units | 0.25 mL | 0.3, 0.5 or 1 mL |
| 30 units | 0.30 mL | 0.3, 0.5 or 1 mL |
| 40 units | 0.40 mL | 0.5 or 1 mL |
| 50 units | 0.50 mL | 0.5 or 1 mL |
| 75 units | 0.75 mL | 1 mL |
| 100 units | 1.00 mL | 1 mL |
A worked example
25 U-100 markings ÷ 100 = 0.25 mL. The volume fits within all three supported barrel capacities; the actual marked divisions still need to match.
How many mL is 20 units?
On a U-100 syringe, 20 marked units represent 0.20 mL: divide 20 by 100. This is a volume conversion, not a recommended amount. The mass in that volume depends on the concentration of the solution.
Does syringe size change units to mL?
No. For U-100 syringes, 1 marked unit represents 0.01 mL on every barrel size. Capacity changes how much fits: 30 units in 0.3 mL, 50 in 0.5 mL and 100 in 1 mL. It does not change the conversion.
Can every converted volume be measured?
Not necessarily. Half-unit, 1-unit and 2-unit divisions represent 0.005, 0.01 and 0.02 mL respectively. A result between divisions is mathematically valid but does not create a new line on the barrel. The nearest line is a comparison only.
Do I need the vial concentration?
Concentration is not needed to convert U-100 markings to mL. It is needed to work out the mass in mg or mcg. This page cannot convert biological IU or markings on a different syringe scale.
What this conversion cannot tell you
This relationship only applies to the U-100 volume scale. It does not tell you a dose, biological activity or mass in mg.
Source: BD: U-100 syringe capacities and markings. Supports the device scale and capacity context. Formula examples are arithmetic derived from the stated U-100 scale. Source checked 17 October 2026. This checks the cited device or unit context, not treatment suitability.