25 units to mL
25 units to mL on a U-100 insulin syringe, which syringe it fits, and how much peptide it holds at common strengths.
25 units is 0.25 mL on a U-100 insulin syringe.
On a U-40 syringe the same 25 units would be 0.625 mL. It fits a 0.3 mL (30 unit) U-100 syringe.
With a U-100 insulin syringe, 25 units works out to 0.25 mL, a quarter of a millilitre.
- 0.25 mL is what 25 units measures on a U-100 syringe
- 0.625 mL is what 25 units measures on a U-40 syringe
- The smallest option, a 0.3 mL (30 unit) U-100 syringe, holds 25 units with room to spare
On a U-100 syringe, 100 units fill exactly 1 mL. Look for "U-100" or "U-40" on the label or box before you draw, and make sure it matches your insulin.
Syringes that measure 25 units
Every syringe size has its own scale. The small marks printed on the barrel are the ticks, and each tick means a different amount depending on the size of the syringe.
| Syringe | Units in a full syringe | Amount per tick | Where 25 units sits |
|---|---|---|---|
| 0.3 mL U-100 | 30 units | each tick = 1 unit | at the 25 tick mark |
| 0.5 mL U-100 | 50 units | each tick = 1 unit | at the 25 tick mark |
| 1 mL U-100 | 100 units | each tick = 2 units | halfway between two tick marks |
| 1 mL U-40 syringe | 40 units of insulin | each tick = 1 unit | the 25 tick mark, which is 0.625 mL |
A 0.3 mL syringe or a 0.5 mL syringe marks every single unit, so 25 units is easy to spot. Count 25 ticks along the barrel, or read the 25 printed there.
Drawing 25 units with a 1 mL syringe
With a 1 mL syringe marked U-100, every tick stands for 2 units. That puts 25 units halfway between two tick marks, and there is no line for 25 itself. It takes more care to read by eye, so a 0.3 mL or 0.5 mL syringe is easier for this amount.
What changes with U-40 syringes
A U-40 syringe fits 40 units into 1 mL, so every unit is a larger amount of liquid. When you draw it up to the 25 mark, you get 0.625 mL. That is two and a half times the liquid you would get from 25 units on a U-100 syringe. Never use a U-40 syringe with U-100 insulin, or a U-100 syringe with U-40 insulin, because it changes your dose.
How much medicine do 25 units hold?
Syringe markings show units for the type of insulin the syringe is made for. If you're measuring a different medicine, check the strength on your vial's label and ask your pharmacist how many units make up your dose.
Convert another amount
Questions people often ask
Does 2.5 units equal 25 units?
No. 2.5 units is a much smaller dose, just a tenth of 25 units. It is only a tiny amount of liquid, so double-check where the decimal point sits on your prescription. If your dose is written in milligrams, ask your pharmacist how many units that is for your vial.
Does 20 units mean 0.5 mL or 1 mL?
Not either one. With a U-100 syringe, 20 units measures 0.2 mL. You would need 50 units to fill 0.5 mL, and 100 units to fill 1 mL.
Does the size of the needle affect the reading?
No. The gauge, meaning the thickness of the needle, and the needle length do not change the tick readings. The reading on a 0.3 mL U-100 syringe is the same whether the needle is 30 gauge or 31 gauge.