Syringe units ↔ mL
Insulin syringes are marked in “units” instead of milliliters. Type a number in either box and the other updates instantly.
The number you see on an insulin syringe
The actual volume of liquid
On a U-100 insulin syringe, 100 units always equals 1 mL.
Quick reference
What are syringe units?
Insulin syringes use a special scale called “units” instead of milliliters (mL). This scale was designed for insulin, but the same syringes are commonly used for peptide injections.
On a U-100 syringe (the most common type), the conversion is simple: 100 units = 1 mL. So each unit is 0.01 mL — a tiny amount of liquid.
How do I read my syringe?
Look at the markings on the barrel of your syringe. Most insulin syringes have numbers printed along the side — those are units.
- 0.3 mL syringe — goes up to 30 units, each tiny line = 0.5 units
- 0.5 mL syringe — goes up to 50 units, each line = 1 unit
- 1 mL syringe — goes up to 100 units, each line = 1 unit
When a plan says “draw 10 units,” pull the plunger back until the top of the rubber stopper lines up with the 10 mark.
Why not just use mL?
Syringe units exist because insulin doses are very small — often just a few hundredths of a milliliter. Saying “10 units” is easier and less error-prone than saying “0.1 mL.”
For peptide reconstitution, working in units makes dosing simpler. That's why our plan builder gives you your dose in units — just draw to that line on your syringe.