Units to mL: how many units are in 1 mL?
Updated 24 October 2026
A U-100 insulin syringe has 100 units in 1 mL, so 1 unit is 0.01 mL and 10 units is 0.1 mL. A U-40 syringe has 40 units in 1 mL, so 1 unit is 0.025 mL.
Nearly every insulin syringe sold for people in the US is U-100. U-40 syringes are made for pet insulin. The scale is printed on the syringe and its box; check it before converting.
Units to mL converter
0.1 mL on a U-100 syringe · 0.25 mL on a U-40 syringe
25 units on a U-100 syringe · 10 units on a U-40 syringe
Units to mL table
| Units | U-100 syringe | U-40 syringe |
|---|---|---|
| 1 | 0.01 mL | 0.025 mL |
| 2 | 0.02 mL | 0.05 mL |
| 5 | 0.05 mL | 0.125 mL |
| 10 | 0.1 mL | 0.25 mL |
| 12.5 | 0.125 mL | 0.313 mL |
| 15 | 0.15 mL | 0.375 mL |
| 20 | 0.2 mL | 0.5 mL |
| 25 | 0.25 mL | 0.625 mL |
| 30 | 0.3 mL | 0.75 mL |
| 40 | 0.4 mL | 1 mL |
| 50 | 0.5 mL | over 1 mL |
| 60 | 0.6 mL | over 1 mL |
| 75 | 0.75 mL | over 1 mL |
| 100 | 1 mL | over 1 mL |
Why the syringe scale matters
The same number means a different volume on each scale. 10 units on a U-40 syringe is 0.25 mL, two and a half times the 0.1 mL that 10 units means on a U-100 syringe. If your instructions are written in units, they assume a particular syringe, almost always U-100.
Units are volume, not dose
Outside insulin, the units on a syringe say nothing about how much drug you take. That depends on the concentration of the vial. To go from a dose in mg to units, use the mg to units calculator.