Tirzepatide Calculator
Use the Tirzepatide calculator below to work out reconstitution, syringe units, concentration, and doses per vial. Enter your vial size, the volume of bacteriostatic water you plan to add, and your desired dose — the calculator returns exact draw amounts in mL and syringe units, plus mg/mL and mcg/unit conversions. This page is math only: it does not recommend a Tirzepatide dose or endorse human use.
1. Syringe details
Pick the syringe you're drawing into.
2. Vial details
Add each peptide in the vial and the bacteriostatic water you'll mix in.
Total peptide in vial
10 mg
3. Desired dose
The amount per injection you'd like to draw.
How this calculator works
The Tirzepatide calculator covers everything: reconstitution ratio, mg/mL concentration, mcg per syringe unit, exact draw volume in mL and units, plus doses per vial.
Reconstitution formula
- Concentration (mg/mL) = total peptide mg ÷ water mL
- Draw volume (mL) = desired dose mg ÷ concentration mg/mL
- Draw units = draw mL × units-per-mL of your syringe
- mcg per unit = (total mg × 1000) ÷ total units of water added
- Doses per vial = total peptide mg ÷ desired dose mg
Syringe units explained
| Syringe | Capacity | Ticks (units) | Units per mL | Per unit |
|---|---|---|---|---|
| U-100 · 1 mL | 1 mL | 100 | 100 | 0.01 mL |
| U-100 · 0.5 mL | 0.5 mL | 50 | 100 | 0.01 mL |
| U-100 · 0.3 mL | 0.3 mL | 30 | 100 | 0.01 mL |
| U-40 · 1 mL | 1 mL | 40 | 40 | 0.025 mL |
mL, mg, mcg & units conversion
- 1 mL = 100 U-100 units = 40 U-40 units
- 1 mg = 1000 mcg = 0.001 g
- On a U-100 syringe, 1 unit = 0.01 mL
- On a U-40 syringe, 1 unit = 0.025 mL
Common calculation mistakes
- Confusing U-100 and U-40 syringes — units are not interchangeable.
- Mixing mg and mcg without converting (1 mg = 1000 mcg).
- Assuming 1 unit = 1 mL — 1 unit on a U-100 syringe is 0.01 mL.
- Forgetting that adding more bacteriostatic water lowers concentration and increases draw volume.
- Rounding aggressively — always keep at least one decimal for draw units.
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Frequently asked questions
Tirzepatide is often sold as 5, 10, or 15 mg vials — how does that affect the math?+
Vial size is the total peptide in the vial. The calculator uses total mg ÷ water mL to compute concentration, so larger vials at the same water volume yield higher mg/mL and lower draw units for the same dose.
How do I convert Tirzepatide mcg to syringe units?+
Enter your desired dose in mcg (toggle the unit selector). The calculator converts internally to mg and returns exact units to draw for the syringe you selected.
How do I calculate reconstitution?+
Divide the total peptide mass in the vial by the volume of bacteriostatic water you added. That gives concentration in mg/mL. Divide your desired dose (in mg) by that concentration to get the volume to draw in mL, then multiply by the syringe's units-per-mL.
What is a U-100 insulin syringe?+
A U-100 syringe has 100 tick marks on a 1 mL barrel — so 100 units = 1 mL, and each unit = 0.01 mL. U-100 0.5 mL and 0.3 mL barrels have 50 and 30 ticks respectively, but the units-per-mL is the same.
How many mcg are in one syringe unit?+
It depends on the vial. Multiply the total peptide in mg by 1000 to get mcg, then divide by the total units of water added (mL × units-per-mL). PeptideCalc Pro shows this as mcg/unit automatically.
Is this calculator medical advice?+
No. PeptideCalc Pro is a math tool for educational and research use only. It does not recommend doses or endorse human use. Always consult a licensed medical professional.