Tirzepatide Dosage Calculator
This tirzepatide dosage calculator answers the two questions a powder vial lands on you at once: how much BAC water to add, and how many units your dose then is. It works in either direction, for any vial from 5 to 60 mg, and it opens in reconstitution mode, the way most tirzepatide searches arrive.
Units measure volume, not dose. The same units on a different mix are a different dose.
The link holds only the numbers you typed. No account, no tracking, nothing else.
On this page
BAC water amounts for a 5 mg dose
If your dose is 5 mg, here is the water that lands it exactly on a round draw, for the two vial sizes it most often comes in. The engine solved for these, the same way the calculator above does.
| Vial | For a 25 unit draw | For a 50 unit draw |
|---|---|---|
| 20 mg | Add 1 mL, get 25 units | Add 2 mL, get 50 units |
| 40 mg | Add 2 mL, get 25 units | Add 4 mL, get 50 units |
The pattern is the same one the general reconstitution calculator is built on: bigger vial, more water for the same draw, because the water has to stretch across more doses.
Tirzepatide dosage calculator in units: 20 mg vial, 2 mL of water
This mix is 10 mg per mL, so each unit holds 0.1 mg and the numbers stay tidy.
| Dose | Draw in units | Draw in mL |
|---|---|---|
| 2.5 mg | 25 units | 0.25 mL |
| 5 mg | 50 units | 0.5 mL |
| 7.5 mg | 75 units | 0.75 mL |
| 10 mg | 100 units | 1 mL |
A note on 50 unit syringes
A lot of tirzepatide is drawn with the smaller 0.5 mL syringe, sold as a "50 unit syringe". The name confuses people into thinking its units are a different size. They are not. It is a U-100 syringe that simply stops at 50, and one unit on it is the same 0.01 mL as one unit on the 1 mL size.
The real catch is capacity. Mix a vial weak and a larger dose can run past 50 units, and then it cannot be drawn in one go. That is a mixing problem, not a syringe problem: less water makes the same dose fit. The calculator flags it the moment you pick the 0.5 mL syringe and the draw goes over.
Common questions
How much BAC water do I add to a 10 mg tirzepatide vial?
It is your call, and the calculator above works in reverse to help you make it: pick the draw you want for your dose and it tells you the water. With 2 mL, a 10 mg vial mixes to 5 mg per mL, so a 2.5 mg dose is a 50 unit draw. With 1 mL the mix is twice as strong and the same dose is 25 units.
How many units is 2.5 mg of tirzepatide?
It depends on the mix, like every unit answer. At 5 mg per mL (say a 10 mg vial in 2 mL, or a 20 mg vial in 4 mL), 2.5 mg is 50 units. At 10 mg per mL (a 20 mg vial in 2 mL), it is 25 units. The dose has not changed. Only the water has.
I use a 50 unit syringe. Does that change anything?
The units themselves do not change. A 50 unit syringe is a 0.5 mL U-100 syringe, and the marks mean the same volume as on any other U-100 syringe. What changes is the limit: a draw over 50 units will not fit. Pick the 0.5 mL syringe in the calculator and it will warn you when a combination goes past it.
How many doses are in a 20 mg tirzepatide vial?
Vial amount divided by dose. At 5 mg a dose, a 20 mg vial holds 4 doses. At 2.5 mg a dose, it holds 8. The water amount does not change the count, only the size of each draw. The calculator shows the count, and any leftover, for your own numbers.
Why does my tirzepatide draw look different from the chart in a forum post?
Because the forum post assumed a mix, probably without saying so. Charts are only true for the vial size and water amount they were built on. If your vial or your water differs, your units differ too, and your numbers are the right ones for your vial.
Arithmetic only
This calculator does maths on the numbers you enter. It works out concentration, draw volume and syringe units from the vial amount and water volume you give it. Nothing more.
It does not recommend amounts, schedules or products, and it does not know what is in your vial. It uses the amount printed on the label. If the label and the actual contents differ, the result differs too. For medical questions, talk to a clinician.
How the maths works, and where the facts on this site come from: Methodology and sources.