Syringe units to mL converter
Convert the unit marks on an insulin syringe to milliliters, and back, for U-100, U-50 and U-40 syringes.
Medically reviewed by Dr. Nezar Dahdal, Medical Director · last reviewed September 2026
Syringe units to mL converter
Type in either box. Most injection syringes in the US are U-100, where 100 units fill 1 mL. The syringe type is printed on the barrel or the box.
25 units on a U-100 syringe = 0.25 mL
Units here are marks on the syringe, a measure of volume. How much medication a unit contains depends on the concentration of what is in the vial.
Units to mL table
For U-100 syringes, the type used for almost all injections at home in the US.
| Units | U-100 | U-50 | U-40 |
|---|---|---|---|
| 1 units | 0.01 mL | 0.02 mL | 0.025 mL |
| 5 units | 0.05 mL | 0.1 mL | 0.125 mL |
| 10 units | 0.1 mL | 0.2 mL | 0.25 mL |
| 20 units | 0.2 mL | 0.4 mL | 0.5 mL |
| 25 units | 0.25 mL | 0.5 mL | 0.625 mL |
| 30 units | 0.3 mL | 0.6 mL | 0.75 mL |
| 40 units | 0.4 mL | 0.8 mL | 1 mL |
| 50 units | 0.5 mL | 1 mL | 1.25 mL |
| 60 units | 0.6 mL | 1.2 mL | 1.5 mL |
| 75 units | 0.75 mL | 1.5 mL | 1.875 mL |
| 100 units | 1 mL | 2 mL | 2.5 mL |
How to read a syringe
A syringe's type tells you how many units fill one milliliter. U-100 is the standard in the US: 100 units in 1 mL, so each unit mark is 0.01 mL. Syringes also come in different capacities. A 30-unit syringe holds 0.3 mL and a 50-unit syringe holds 0.5 mL, with finer marks that make small volumes easier to measure.
Mixing up syringe types is a measurement error, not a small one: the same number of units is 2.5 times the volume on a U-40 syringe as on a U-100. If you are unsure which you have, check the barrel or ask your pharmacist.
Answers before you book
How many units are in 1 mL?
On a U-100 syringe, 1 mL is 100 units. On a U-50 syringe it is 50 units, and on a U-40 syringe it is 40 units. The syringe type is printed on the barrel.
How many mL is 50 units?
On a U-100 syringe, 50 units is 0.5 mL. On a U-40 syringe, 50 units would be 1.25 mL, which is why the syringe type matters.
Is 10 units the same as 0.1 mL?
Yes, on a U-100 syringe. Each unit mark is 0.01 mL.
Does a unit mean the same amount of medication in every vial?
No. A unit is a volume mark on the syringe. How much medication it holds depends on the concentration of the vial. For GLP-1 medications, use the dose calculators, which account for concentration.
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