Tools / Units to dose
Units to dose calculator
Already drawn your U-100 syringe? Enter your vial, the water you mixed in and the units you drew to see exactly how much peptide that is.
Example: 10 units from a 5 mg vial mixed with 2 mL water is 250 mcg (0.25 mg).
The mg printed on the vial label.
Bacteriostatic (bac) water, in mL.
The line on your insulin syringe.
It's printed on the packet: 0.3, 0.5 or 1 mL.
5 mg vial + 2 mL water, 10 units drawn
That draw holds
250mcg
Which is 0.25 mg, or 0.1 mL of liquid.
- Strength after mixing
- 2.5 mg/mL
- Each unit holds
- 25 mcg
- Doses this size in the vial
- 20
Show the math
- 10 units ÷ 100 = 0.1 mL
- 5,000 mcg ÷ 2 mL = 2,500 mcg/mL
- 0.1 mL × 2,500 mcg/mL = 250 mcg
Not what you expected? Check the numbers above, and confirm with your prescriber or pharmacist before you inject.
Checked 8 November 2026 by the PeptideTracker editorial team · This tool does the math only. It doesn't recommend a dose.
[02] Units table
What 10, 20 and 50 units hold
Dose in mcg for each vial size, mixed with 2 mL of water.
| Vial | 10 units | 20 units | 50 units |
|---|---|---|---|
| 5 mg | 250 mcg | 500 mcg | 1,250 mcg |
| 10 mg | 500 mcg | 1,000 mcg | 2,500 mcg |
| 15 mg | 750 mcg | 1,500 mcg | 3,750 mcg |
| 20 mg | 1,000 mcg | 2,000 mcg | 5,000 mcg |
| 30 mg | 1,500 mcg | 3,000 mcg | 7,500 mcg |
[03] How it works
Units are volume, not dose
An insulin syringe measures liquid. On a U-100 syringe, 1 unit is 0.01 mL. To know how much peptide is in that liquid, you need the strength of your mixed vial.
- Divide the units by 100 to get mL.
- Divide the mcg in the vial by the mL of water to get the strength.
- Multiply the mL you drew by the strength.
[04] Questions
Questions
How many units are in 1 mg?
On a U-100 syringe, 1 mg is 40 units from a 5 mg vial mixed with 2 mL, and 20 units from a 10 mg vial mixed with 2 mL. The formula is units = mg ÷ strength in mg/mL × 100.
How many mcg are in 1 unit?
25 mcg from a 5 mg vial mixed with 2 mL, and 50 mcg from a 10 mg vial mixed with 2 mL. It's the strength in mcg per mL divided by 100.
How many mg is 10 units?
With 5 mg of peptide in 2 mL of water, 10 units (0.1 mL) holds 250 mcg, which is 0.25 mg. With 10 mg in 2 mL, 10 units holds 0.5 mg.
Is 10 units the same as 10 mg?
No. Units on an insulin syringe measure volume: 100 units is 1 mL. How many mg are in that volume depends on how much peptide and water are in the vial.
How many units are in 1 mL?
On a U-100 insulin syringe, 1 mL is 100 units, so 0.5 mL is 50 units and 0.1 mL is 10 units.
Why is my dose different from someone else's at the same units?
Because their vial may be a different size or mixed with a different amount of water. The same 10 units can hold very different amounts of peptide.
Spotted a mistake or something out of date? Tell us. We aim to fix factual errors within two working days.
[05] Read next
Guides that go with this calculator
- Tirzepatide dosage chart: mg, mL and unitsPrescriptions say mg and syringes say units. This chart lines up each Mounjaro and Zepbound label dose with its mL and U-100 units.
- Semaglutide dosage chart: mg, mL and unitsPens give you a set dose in mg. If your semaglutide comes from a vial, each label dose also has to become mL and syringe units.
- How to read an insulin syringeThe numbers on the barrel are units of liquid, not milligrams of medicine. To read one correctly, check the scale, line up the top edge of the plunger with your number and clear any air.
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