Tirzepatide dose calculator

Using tirzepatide from a vial? Enter the mg on the vial, the water in it and your weekly dose in mg, and see where to draw on your syringe.

Have you mixed your vial with water yet?

How much tirzepatide is in the vial?

It's printed on the vial label, for example 10mg. This is the powder before any water goes in.

Where is it on the label?

The amount is the big figure on the label, in mg. Ignore the volume of water or the batch number.

What dose were you told to take?

Use the number and unit exactly as you were given it. Doses under 1 mg are usually written in mcg (micrograms). 1 mg is 1,000 mcg.

How much water did you add?

Bacteriostatic water, in mL. If you're not sure, check what you wrote down when you mixed it.

Which syringe do you have?

Look at the biggest number printed on the side of the syringe.

Not sure? See the three sizes

All three are U-100 insulin syringes: 100 units is 1 mL. The top mark tells you which one you have. A 1 mL syringe has a line every 2 units, so count carefully.

Draw to

25 units

Pull the plunger back until the edge of the dark stopper nearest the needle lines up with 25. On your syringe each small line is 2 units, so this sits between the 24 and 26 lines.

Reading it back: 10 mg vial, mixed with 1 mL water, dose of 2.5 mg. That's 0.25 mL, and the vial holds about 4 doses.

This falls between the lines. The nearest line on your syringe is 26 units.

Show the maths

strength = 10 mg ÷ 1 mL = 10 mg/mL
volume = 2.5 mg ÷ 10 mg/mL = 0.25 mL
units = 0.25 mL × 100 = 25 units

Every dose from this vial

10 mg in 1 mL on a 1 mL syringe, in 0.5 mg steps. Your dose is whatever you were given; this only converts it.
Dose	Volume	Units	On the syringe
0.5 mg	0.05 mL	5	between lines, nearest 6
1 mg	0.1 mL	10	on a line
1.5 mg	0.15 mL	15	between lines, nearest 16
2 mg	0.2 mL	20	on a line
2.5 mg	0.25 mL	25	between lines, nearest 26
3 mg	0.3 mL	30	on a line
3.5 mg	0.35 mL	35	between lines, nearest 36
4 mg	0.4 mL	40	on a line
4.5 mg	0.45 mL	45	between lines, nearest 46
5 mg	0.5 mL	50	on a line
5.5 mg	0.55 mL	55	between lines, nearest 56
6 mg	0.6 mL	60	on a line
6.5 mg	0.65 mL	65	between lines, nearest 66
7 mg	0.7 mL	70	on a line
7.5 mg	0.75 mL	75	between lines, nearest 76
8 mg	0.8 mL	80	on a line
8.5 mg	0.85 mL	85	between lines, nearest 86
9 mg	0.9 mL	90	on a line
9.5 mg	0.95 mL	95	between lines, nearest 96
10 mg	1 mL	100	on a line

Printed from DoseClear. Reopen this exact answer:

Next time it opens with your numbers. Stays on this device.

This is a maths tool, not medical advice. If anything here doesn't match what you were told, check with your prescriber or pharmacist before you go ahead. Found an error?

Divide the mg in the vial by the mL of liquid to get the strength, then divide your dose by the strength and multiply by 100 for units. Example: a 10 mg vial with 1 mL is 10 mg/mL, so a 2.5 mg dose is 0.25 mL, which is 25 units on a U-100 syringe.

Every step is shown

Open "Show the maths" and you can check each line yourself, or show it to someone you trust.

We catch the common slips

Mixing up mg and mcg, or picking the wrong syringe, are the usual mistakes. We flag both before you draw.

Nothing to sell you

No shop, no seller links, no account. Your numbers stay on your device.

Tirzepatide dose chart, from the FDA label

These are the steps in the FDA-approved prescribing information for Mounjaro and Zepbound, the branded forms of tirzepatide. They are what the label says, not advice for you: your prescriber sets your dose.

Stage	Weekly dose	What the label says
Start	2.5 mg	For 4 weeks. The starting dose is not intended as a treatment dose.
Step up	5 mg	After 4 weeks on 2.5 mg.
Further steps	7.5, 10, 12.5 mg	Increases of 2.5 mg, each after at least 4 weeks on the current dose.
Maximum	15 mg	The highest dose on the label.

Those doses in syringe units

How far each label dose sits on a 1 mL (100 unit) syringe, for common compounded vial strengths. Branded single-dose pens don't need this: they deliver a fixed dose.

2.5 mg on a 1 mL U-100 syringe
Vial	Water	Strength	2.5 mg is	Doses per vial
10 mg	1 mL	10 mg/mL	25 units (0.25 mL)	4
10 mg	2 mL	5 mg/mL	50 units (0.5 mL)	4

5 mg on a 1 mL U-100 syringe
Vial	Water	Strength	5 mg is	Doses per vial
10 mg	1 mL	10 mg/mL	50 units (0.5 mL)	2
10 mg	2 mL	5 mg/mL	100 units (1 mL)	2

The 10x mistake with compounded GLP-1 medicines

The FDA has reports of people taking five to twenty times their intended dose of compounded GLP-1 medicines, often from confusing units, mL and mg when drawing from a vial (FDA alert). If your pharmacy gave you a dose in units, check it here against the mg on your prescription before you draw.

Sources

Mounjaro (tirzepatide) prescribing information, Eli Lilly, FDA label: accessdata.fda.gov
Zepbound (tirzepatide) prescribing information, Eli Lilly, FDA label: accessdata.fda.gov
FDA alert on dosing errors with compounded GLP-1 injectables: fda.gov

Last checked 2026-10-07.

Other calculators

Peptide calculatorAny single peptide vial MixingHow much water to add BlendsTwo peptides in one vial RetatrutideSet up for weekly mg doses TrackerComing soon: join the waitlist