Syringe units converter
Convert between millilitres and the unit scale printed on an insulin syringe. U-100 means 100 units per millilitre; U-40 means 40.
Common draws on U-100 and U-40
| Units | mL on U-100 | mL on U-40 | Fits a 0.3 mL barrel? |
|---|---|---|---|
| 1 | 0.01 | 0.025 | Yes |
| 2 | 0.02 | 0.05 | Yes |
| 4 | 0.04 | 0.1 | Yes |
| 5 | 0.05 | 0.125 | Yes |
| 8 | 0.08 | 0.2 | Yes |
| 10 | 0.1 | 0.25 | Yes |
| 12 | 0.12 | 0.3 | Yes |
| 15 | 0.15 | 0.375 | Yes |
| 20 | 0.2 | 0.5 | Yes |
| 25 | 0.25 | 0.625 | Yes |
| 30 | 0.3 | 0.75 | Yes |
| 40 | 0.4 | 1 | 0.5 mL or larger |
| 50 | 0.5 | 1.25 | 0.5 mL or larger |
| 60 | 0.6 | 1.5 | 1 mL only |
| 75 | 0.75 | 1.875 | 1 mL only |
| 80 | 0.8 | 2 | 1 mL only |
| 100 | 1 | 2.5 | 1 mL only |
What a unit is
A unit on an insulin syringe is one hundredth of a millilitre on the U-100 scale. The scale exists so the barrel can be read in whole numbers rather than in fractions of a millilitre. Because it is a scale and not a volume, a U-40 barrel divides each millilitre into 40 instead of 100, and the same volume reads as a smaller number of units. The two scales should never be mixed: 10 units on U-100 is 0.1 mL, while 10 units on U-40 is 0.25 mL, two and a half times as much.
Barrel size does not change the scale. A 0.3 mL, 0.5 mL and 1 mL U-100 syringe all deliver 0.01 mL per unit. The small barrel tops out at 30 units, the middle one at 50, the large one at 100, and the tick marks are spaced further apart on the small barrel, which is why it is easier to read for draws under 30 units. The syringe guide covers the markings in detail.
Questions
How many units are in 1 mL?
On a U-100 insulin syringe, 100 units. On a U-40 syringe, 40 units. The unit is a scale printed on the barrel, not a fixed volume, so always read which scale the barrel uses.
How many mL is 10 units?
0.1 mL on a U-100 syringe (10 ÷ 100) and 0.25 mL on a U-40 syringe (10 ÷ 40).
Are units the same on a 0.3 mL, 0.5 mL and 1 mL syringe?
Yes, if all three are U-100. Each holds 100 units per mL; the barrel size only changes the maximum (30, 50 or 100 units) and how far apart the tick marks sit.
What does one tick mark mean?
It depends on the barrel. Most 0.3 mL U-100 barrels mark every unit or every half unit, 0.5 mL barrels every unit, and 1 mL barrels every two units. Read the printed numbers and count the ticks between them.
Brands we recommend. We are independent and have no affiliation with any brand: no affiliate links, no referral codes, no paid placements. These are the suppliers whose testing and certificates hold up when we check them.
- Licensed Peptides two accredited labs on every lot, certificates public, card and Apple Pay checkout
- Core Peptides long track record, public certificates, wide catalog
- Ascension Peptides public third-party testing, clear pricing