Reconstitution calculator
You mixed a vial. Your prescriber gave you a dose in milligrams. Your syringe is marked in units. This converts between them and shows the working, so you can check it rather than trust it.
10units
to draw on a U-100 (100-unit) insulin syringe
concentration 5 mg/mL · 0.1 mL per dose
Show the arithmetic
- concentration = 10 mg ÷ 2 mL = 5 mg/mL
- volume = 0.5 mg ÷ 5 mg/mL = 0.1 mL
- units = 0.1 mL × 100 = 10 units
A U-100 syringe is marked so that 100 units = 1 mL. That is the only reason the last step is a multiplication by 100 — if your syringe is marked differently, this number does not apply.
Why the same vial gives different unit numbers
The peptide amount is fixed by the vial. The concentration is not — it depends entirely on how much bacteriostatic water you added. Ten milligrams in 1 mL is twice as concentrated as ten milligrams in 2 mL, so the same 0.5 mg dose is 5 units in the first case and 10 units in the second. This is the single most common source of confusion, and it is why there is no universal "units per mg" answer to look up: the number depends on a choice you made at the sink.
Check your syringe is actually U-100
This calculator assumes a U-100 insulin syringe, where 100 units equals 1 mL. That is the common type, but U-40 syringes exist (often for veterinary use) and are marked differently. If yours is not U-100, the unit number here does not apply to it.
Keep a record of what you actually drew
The arithmetic is the easy part. What is harder over months is remembering which site you last used, when the current vial expires, and whether the side effects you had last week lined up with a dose change. Titr tracks that — the dose log, injection-site rotation, and your weight against every dose change on one chart.