MATH · FREE

Tirzepatide Calculator

Vial and syringe arithmetic for a tirzepatide powder that has to be mixed: concentration, mL to draw and units on a U-100 insulin syringe. You type every number from your label or prescriber.

Pens do not need this

Branded tirzepatide pens are prefilled and are not reconstituted (FDA label). This calculator is only for a product your prescriber or pharmacist told you to mix. It does not suggest any amount.

Math only. Not medical advice. This page does not recommend, suggest or check any dose. Use only the numbers from your prescriber, pharmacist or product label.

Example vial amounts (enter what is on your label):

Made-up example numbers for arithmetic only. Replace every box with the numbers from your own label or prescriber.

DRAW ON A U-100 SYRINGE

    Syringe diagram

    Concentration

    Per syringe unit

    of peptide in 1 unit

    Volume to draw

    Doses per vial

    whole doses, rounded down

    Math only. Not medical advice. This page does not recommend, suggest or check any dose. Use only the numbers from your prescriber, pharmacist or product label. Always check the numbers against your prescriber's or product's instructions.

    AFTER YOU MEASURE

    Measured it? Log the dose.

    Log the dose and rotate injection sites in Orbido, a private log and reminder app for iPhone. No account, data stays on your device. Orbido is a logging tool, not medical advice.

    Meet Orbido

    Quick converters

    Units ↔ mL (U-100)

    mg ↔ mcg

    Worked example (made-up numbers)

    These numbers show the arithmetic and are not a suggested amount. Say a vial label reads 10 mg, you add 2 mL of water, and the amount you want in the syringe is 600 mcg.

    1. Concentration. 10 mg ÷ 2 mL = 5 mg/mL, which is 5,000 mcg per mL.
    2. Volume. 600 mcg ÷ 5,000 mcg/mL = 0.12 mL.
    3. Units. 0.12 mL × 100 = 12 units on a U-100 syringe.
    4. Per unit. 5,000 mcg/mL ÷ 100 = 50 mcg in each unit.
    5. Draws per vial. 10,000 mcg ÷ 600 mcg = 16.67, so 16 whole draws before any waste.

    What changes if you add more water

    With the same 10 mg vial and 3 mL of water, the concentration drops to about 3.33 mg/mL and the same 600 mcg becomes 0.18 mL, or 18 units. The amount in the vial has not changed, only how it is spread through the liquid. A larger volume is easier to read on the syringe marks, which is why the calculator warns about draws under 2 units.

    About the vial buttons

    The buttons above the calculator (5, 10, 15, 20, 30 mg) are example amounts that fill in the vial box so you can see how the numbers move. Enter what is printed on your label. This page does not say which products or sizes exist, and it does not endorse compounded or research-labeled vials. Follow the instructions from your prescriber and pharmacy.

    Sources

    Frequently asked questions

    Do I need a reconstitution calculator for tirzepatide?

    Only if your product is a powder in a vial that must be mixed with water before use, and your prescriber or pharmacist told you to mix it. The FDA label for the branded product describes a ready-to-use solution in prefilled pens, which are not reconstituted. If you use a pen, you do not need this calculator.

    How do I work out the concentration of a mixed vial?

    Divide the amount of tirzepatide in the vial by the volume of water added. 10 mg in 2 mL is 5 mg/mL; 10 mg in 3 mL is about 3.33 mg/mL. More water gives a weaker concentration and a larger volume for the same amount.

    How do I convert mL to units on an insulin syringe?

    A U-100 insulin syringe has 100 units per mL. Multiply the mL to draw by 100. In the made-up example on this page, 0.12 mL is 12 units. The units are a volume mark, not a measure of medicine strength.

    What do the vial buttons mean?

    They only fill in the vial amount box with an example number (5, 10, 15, 20 or 30 mg) so you can try the arithmetic. They are not suggestions and not a list of what exists. Always type the amount printed on your own label.

    Does this tell me how much tirzepatide to use or how often?

    No. It never suggests an amount, a schedule or a change. Those come from your prescriber and the labeling for your product. The calculator only divides numbers you enter.

    Math only. Not medical advice. This page does not recommend, suggest or check any dose. Use only the numbers from your prescriber, pharmacist or product label.

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