How this calculator works
A milligram measures mass; U-100 markings represent volume. This tool starts the target field in mg for that workflow, while keeping the units visible and editable. The required concentration context comes from your vial mass and final solution volume.
Formula
Target mcg = target mg × 1,000. Target volume = target mcg ÷ concentration in mcg/mL. U-100 marking = volume × 100.
Arithmetic example — not a recommendation
Arithmetic example only: 10 mg in 2 mL gives 5 mg/mL. A user-entered target of 0.5 mg corresponds to 0.1 mL, or 10 U-100 units. At 2.5 mg/mL, the same mass corresponds to 20 units instead.
Scope and assumptions
There is no fixed mg-to-units factor independent of concentration. U-100 scale units here are not international units of biological activity.
Mass is normalized to mcg; volume stays in mL. Where shown, U-100 means 100 scale units per mL. Read all formulas and precision rules.