Free tool

Reconstitution calculator

Vial size + bacteriostatic water + your target dose → the exact units to draw on a U-100 insulin syringe. Pure arithmetic, done right every time.

mL

On a U-100 insulin syringe, 100 units = 1 mL. This tool converts volume — it never suggests what dose to take.

Draw to
10
units on your syringe
Concentration: 2.5 mg/mL
Each dose: 0.10 mL · Doses in this vial: 20

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The app does this math on every vial, projects when you'll run out, and reminds you on schedule.

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How the math works

Concentration = peptide ÷ water. A 5 mg vial reconstituted with 2 mL of bacteriostatic water is 2.5 mg/mL (2,500 mcg/mL).

Dose volume = target dose ÷ concentration. A 250 mcg dose at 2,500 mcg/mL is 0.1 mL.

Syringe units = volume × 100 (on any U-100 syringe). 0.1 mL = 10 units. That's the whole trick — everything else is unit conversion.

Want the long version, with worked examples and the classic mistakes? Read the reconstitution guide.

Not medical advice. This calculator converts volumes. It does not recommend compounds or doses — your dose comes from your clinician or your own research.