Dose to units calculator
Convert a prescribed dose in milligrams and a vial concentration in mg/mL into units on a standard U-100 insulin syringe, with every step of the arithmetic shown.
Medically reviewed by Kevin Brandstetter, M.D.Updated September 1, 2026
Read this off your vial label or pharmacy printout. It changes between pharmacies and between fills.
Use the dose written on your prescription, not a dose you are considering.
On a U-100 syringe
10.0 units
That is 0.100 mL, drawn to the 10 unit mark.
- Dose divided by concentration: 0.5 mg / 5 mg/mL = 0.100 mL
- Volume times 100 units/mL: 0.100 mL x 100 = 10.0 units
Check this against your prescriber's instructions and your pharmacy label. If they disagree, stop and call your pharmacist.
This is arithmetic, not a dosing instruction.
The tool converts milligrams to syringe units. It cannot tell you whether a dose is right for you, and it does not replace your prescriber or pharmacist. Do not change your dose, your vial, or your injection technique because of this page. Check the result against your prescription and your pharmacy label, and if they do not match, stop and call your pharmacist before you draw anything up.
Methodology
- How this is calculated
- Volume in mL is your dose in mg divided by the vial concentration in mg/mL. Units are that volume multiplied by 100, because a U-100 syringe is graduated so 100 units is 1 mL. The tool shows the mL figure as well as the unit figure so a wrong input is visible before it becomes a wrong injection.
- Where the data comes from
- Standard unit-conversion arithmetic and the standard U-100 syringe scale. The concentration options are strengths Temi's partner pharmacies print on compounded semaglutide and tirzepatide vials. They are shortcuts for typing, not a statement about your vial.
- Last updated
- September 1, 2026
- What this does not account for
- Syringes on another scale, such as U-40. Dead space in the needle and syringe. Rounding your pharmacy applies. A concentration that changed between fills, which happens and is the single most common cause of a wrong unit reading.
Why milligrams and units are so easy to confuse
A compounded GLP-1 usually arrives as a multi-dose vial. The label states concentration in milligrams per millilitre. The syringe is marked in units. Your prescription is written in milligrams. Nothing in that chain converts itself, and a pre-filled pen, which does, is the product most people have seen before. That gap is where dosing errors happen.
Two numbers drive the answer, and both can change. Concentration differs between pharmacies and can differ between two fills from the same pharmacy. Your prescribed dose changes as you titrate. Getting either wrong changes the result, which is why this tool shows the millilitre step in the middle instead of jumping straight to a unit count.
When to stop and call someone
If the units here do not match what your prescriber or pharmacist told you, do not split the difference. Call your pharmacy. They can see your exact vial, your exact prescription, and the syringe they dispensed, and this page can see none of that. Temi patients can call or text +1 (855) 554-3030 at any hour.
Care that answers the phone
Temi patients reach a person by call, text, or message, 24 hours a day, for exactly this kind of question.
A licensed physician reviews every request. Nothing on this page is a prescription.