Tirzepatide units calculator
Turn your prescribed tirzepatide dose in milligrams into units on an insulin syringe. Free, instant, no signup.
Read this first. This is arithmetic, not a prescription. It converts a dose your prescriber already gave you into syringe units. It does not tell you what dose to take. Always confirm the concentration printed on your own vial, and confirm the final number with the person who prescribed it before you inject anything.
This is the total tirzepatide in the vial and the total liquid volume after reconstitution. Both numbers are on your vial or your pharmacy paperwork.
Common tirzepatide doses: 2.5, 5, 7.5, 10, 12.5, 15 mg
Almost every GLP-1 kit ships U-100.
How the math works
Two steps, no mystery.
1. Find the concentration. Divide the total milligrams in the vial by the total millilitres of liquid. A vial of 5 mg mixed into 2 mL is 2.5 mg per mL.
2. Convert to units. A U-100 insulin syringe is marked so that 100 units equals 1 mL. So one unit is 0.01 mL. Divide your dose by the concentration to get millilitres, then multiply by 100.
For a 0.25 mg dose from a 2.5 mg/mL vial: 0.25 ÷ 2.5 = 0.1 mL, and 0.1 × 100 = 10 units.
Common Tirzepatide Doses in Syringe Units (U-100)
Quick reference for compounded tirzepatide doses drawn on a standard U-100 insulin syringe (100 units = 1.0 mL):
| Prescribed Dose | Vial Concentration | Liquid Volume | Syringe Units |
|---|---|---|---|
| 2.5 mg | 10 mg/mL (10 mg in 1 mL) | 0.25 mL | 25 units |
| 2.5 mg | 20 mg/mL (20 mg in 1 mL) | 0.125 mL | 12.5 units |
| 5.0 mg | 10 mg/mL (10 mg in 1 mL) | 0.50 mL | 50 units |
| 5.0 mg | 20 mg/mL (20 mg in 1 mL) | 0.25 mL | 25 units |
| 7.5 mg | 10 mg/mL (10 mg in 1 mL) | 0.75 mL | 75 units |
| 7.5 mg | 20 mg/mL (20 mg in 1 mL) | 0.375 mL | 37.5 units |
| 10.0 mg | 20 mg/mL (20 mg in 1 mL) | 0.50 mL | 50 units |
| 12.5 mg | 20 mg/mL (40 mg in 2 mL) | 0.625 mL | 62.5 units |
| 15.0 mg | 20 mg/mL (40 mg in 2 mL) | 0.75 mL | 75 units |
Where people get this wrong
Assuming every vial is the same strength
Compounding pharmacies do not use one standard concentration. A 5 mg vial in 2 mL and a 5 mg vial in 1 mL need completely different unit counts for the same dose. Switching pharmacies, or even reordering from the same one, can change the concentration. Re-check every vial.
Confusing units with millilitres
"10 units" and "10 mL" are wildly different amounts. On a U-100 syringe, 10 units is 0.1 mL. Read the numbers printed on the barrel, not the volume on the vial.
Adding a different amount of bacteriostatic water than the instructions say
If you reconstitute the powder yourself, the volume of water you add is the concentration. Add 1 mL instead of 2 mL and every dose you draw is double what you calculated. Use the mL you actually added, not the mL you meant to add.
Rounding on a syringe you cannot read
If your answer lands between markings, do not guess. Ask your prescriber whether to round, or whether a differently marked syringe is appropriate.
The answer for a specific dose
Every common tirzepatide dose has its own page with the number worked out at every concentration a compounding pharmacy is likely to send you, so you can check yours against the full table rather than trusting one figure.
Milligrams to units
Common questions
- Does this work for brand-name pens?
- No. Ozempic, Wegovy, Mounjaro and Zepbound pens are dialled or preset in milligrams. You never draw them into a syringe, so there is nothing to convert. This calculator is for compounded vials.
- My answer is more than 100 units. Is that right?
- It means your dose needs more than a full U-100 syringe at that concentration. That usually signals a data-entry mistake or a very dilute vial. Stop and confirm the vial numbers with your pharmacy.
- Can I use this to increase my own dose?
- No. Titration schedules exist because escalating too quickly drives nausea, vomiting and dehydration. Dose changes come from your prescriber. Use the titration schedule tool to see what a standard escalation looks like so you know what to ask about.
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