mg/mL to units chart
For a vial that is already a liquid, units = mg ÷ mg/mL × 100 on a U-100 insulin syringe. At 10 mg/mL, 1 mg is 10 units; at 5 mg/mL, 1 mg is 20 units. No water volume is needed because the label already gives the concentration.
Units by label concentration
The middle columns show how much each syringe marking holds. The last column is the marking that holds 1 mg, a round reference amount, not a dose. Scale it to the amount on your prescription, or use the calculator below.
| Label concentration | In 1 unit | In 10 units | In 50 units | 1 mg = |
|---|---|---|---|---|
| 1 mg/mL | 0.01 mg · 10 mcg | 0.1 mg · 100 mcg | 0.5 mg · 500 mcg | 100 units |
| 2 mg/mL | 0.02 mg · 20 mcg | 0.2 mg · 200 mcg | 1 mg | 50 units |
| 2.5 mg/mL | 0.025 mg · 25 mcg | 0.25 mg · 250 mcg | 1.25 mg | 40 units |
| 3 mg/mL | 0.03 mg · 30 mcg | 0.3 mg · 300 mcg | 1.5 mg | 33.33 units |
| 4 mg/mL | 0.04 mg · 40 mcg | 0.4 mg · 400 mcg | 2 mg | 25 units |
| 5 mg/mL | 0.05 mg · 50 mcg | 0.5 mg · 500 mcg | 2.5 mg | 20 units |
| 6 mg/mL | 0.06 mg · 60 mcg | 0.6 mg · 600 mcg | 3 mg | 16.67 units |
| 7.5 mg/mL | 0.075 mg · 75 mcg | 0.75 mg · 750 mcg | 3.75 mg | 13.33 units |
| 8 mg/mL | 0.08 mg · 80 mcg | 0.8 mg · 800 mcg | 4 mg | 12.5 units |
| 10 mg/mL | 0.1 mg · 100 mcg | 1 mg | 5 mg | 10 units |
| 12 mg/mL | 0.12 mg · 120 mcg | 1.2 mg | 6 mg | 8.333 units |
| 12.5 mg/mL | 0.125 mg · 125 mcg | 1.25 mg | 6.25 mg | 8 units |
| 15 mg/mL | 0.15 mg · 150 mcg | 1.5 mg | 7.5 mg | 6.667 units |
| 20 mg/mL | 0.2 mg · 200 mcg | 2 mg | 10 mg | 5 units |
| 25 mg/mL | 0.25 mg · 250 mcg | 2.5 mg | 12.5 mg | 4 units |
| 30 mg/mL | 0.3 mg · 300 mcg | 3 mg | 15 mg | 3.333 units |
| 40 mg/mL | 0.4 mg · 400 mcg | 4 mg | 20 mg | 2.5 units |
| 50 mg/mL | 0.5 mg · 500 mcg | 5 mg | 25 mg | 2 units |
| 100 mg/mL | 1 mg | 10 mg | 50 mg | 1 unit · too small to read reliably |
Calculate for a liquid vial
Enter the mg/mL from the label as the amount in the vial. The water is set to 1 mL so the concentration matches the label.
Enter the vial size and the water you added.
Arithmetic only. This tool does not recommend a dose; use the one your prescriber gave you.
Questions
How do I convert mg/mL to units?
Divide the mg you need by the mg/mL on the label to get mL, then multiply by 100 for units on a U-100 insulin syringe. At 10 mg/mL, 1 mg is 0.1 mL, which is 10 units.
My vial is already a liquid. How do I use the calculator?
Enter the mg/mL from the label as the amount in the vial and enter 1 mL as the water. The concentration the calculator shows will then match the label, and the rest of the arithmetic is the same.
How many mg are in one unit?
Divide the mg/mL by 100. At 5 mg/mL one unit holds 0.05 mg (50 mcg). At 10 mg/mL one unit holds 0.1 mg (100 mcg).
Does the total volume in the vial matter?
Not for this conversion. A label such as 10 mg/2 mL means 5 mg/mL; use the per-mL figure. The total volume only tells you how many draws the vial holds.