Tirzepatide Calculator
Enter your Tirzepatide vial size, the water you add and your dose to get the units to draw on a U-100 syringe. The units chart and water table below cover 10, 15, 20, 30, 60 mg vials.
How many units is each Tirzepatide dose?
Units on a U-100 insulin syringe for common amounts, with 2 mL of bacteriostatic water in the vial. With a different water amount, use the calculator above.
| Dose (mg) | 10 mg vial + 2 mL | 15 mg vial + 2 mL | 20 mg vial + 2 mL | 30 mg vial + 2 mL | 60 mg vial + 2 mL |
|---|---|---|---|---|---|
| 2.5 mg | 50 units 0.5 mL | 33.3 units 0.333 mL | 25 units 0.25 mL | 16.7 units 0.167 mL | 8.3 units 0.083 mL |
| 5 mg | 100 units 1 mL | 66.7 units 0.667 mL | 50 units 0.5 mL | 33.3 units 0.333 mL | 16.7 units 0.167 mL |
| 7.5 mg | 150 units* 1.5 mL | 100 units 1 mL | 75 units 0.75 mL | 50 units 0.5 mL | 25 units 0.25 mL |
| 10 mg | 200 units* 2 mL | 133.3 units* 1.333 mL | 100 units 1 mL | 66.7 units 0.667 mL | 33.3 units 0.333 mL |
| 12.5 mg | 250 units* 2.5 mL | 166.7 units* 1.667 mL | 125 units* 1.25 mL | 83.3 units 0.833 mL | 41.7 units 0.417 mL |
| 15 mg | 300 units* 3 mL | 200 units* 2 mL | 150 units* 1.5 mL | 100 units 1 mL | 50 units 0.5 mL |
* More than one 1 mL syringe. Use more water or split the draw.
What does the FDA label say about Tirzepatide dosing?
The FDA prescribing information starts at 2.5 mg once weekly for 4 weeks, then 5 mg once weekly. The dose can go up in 2.5 mg steps after at least 4 weeks on the current dose, up to a maximum of 15 mg once weekly.
Source: FDA prescribing information for Mounjaro and Zepbound. Read the label on DailyMed. Compounded vials aren't FDA-approved, and their strength can differ from brand pens.
How much bac water for Tirzepatide?
Water only changes how much liquid each dose takes up, not how much Tirzepatide is in it. To land a 2.5 mg dose on a round number of units, add:
| Vial | So 2.5 mg = 10 units | So 2.5 mg = 20 units |
|---|---|---|
| 10 mg | 0.4 mL | 0.8 mL |
| 15 mg | 0.6 mL | 1.2 mL |
| 20 mg | 0.8 mL | 1.6 mL |
| 30 mg | 1.2 mL | 2.4 mL |
| 60 mg | 2.4 mL | 4.8 mL |
How do you reconstitute Tirzepatide?
- Concentration: 20 mg ÷ 2 mL = 10 mg/mL (100 mcg per unit).
- Volume to draw: 2.5 mg ÷ 10 mg/mL = 0.25 mL.
- Syringe units: 0.25 mL × 100 = 25 units on a U-100 syringe.
Example numbers only. They come from the default vial, water and amount above, not a recommendation.
What else do people ask about Tirzepatide?
How many units is 2.5 mg of Tirzepatide?
It depends on how much water is in the vial. With a 20 mg vial and 2 mL of water, 2.5 mg is 25 units (0.25 mL) on a U-100 syringe. Change the vial or water amount above to see your number.
How much bacteriostatic water do I add to a Tirzepatide vial?
There's no single right amount. More water makes each unit weaker and the draw bigger, which is easier to measure. Less water makes the draw smaller. Many people pick an amount that puts their dose on a round number of units. The "Units → water to add" tab and the table above work this out.
How many doses are in a 20 mg Tirzepatide vial?
At 2.5 mg per dose, a 20 mg vial holds 8 doses. The amount of water doesn't change this.
Does this page recommend a Tirzepatide dose?
No. The dose schedule quoted above is from the FDA prescribing information for Mounjaro and Zepbound, for reference only. Follow your prescriber's instructions.