The quantities we calculate
M is total entered vial mass, V is final solution volume and D is your known target mass. U-100 units are volume markings. The same core calculation is shared between the general and compound pages.
C (mg/mL) = M (mg) ÷ V (mL)
C (mcg/mL) = 1,000 × M ÷ V
v (mL) = D (mcg) ÷ C (mcg/mL)
U-100 units = v × 100Volume, contents and losses
An added-water input approximates final volume with that added amount. Known final-volume mode uses the quantity you supply directly. Neither mode verifies composition, purity, solvent suitability, physical vial capacity, dissolution or stability.
Theoretical draws and remaining mass exclude dead space and transfer losses. They do not establish how long a prepared solution remains suitable for any use.
Numerical validation
Mass, volume, target amount and capacity must be positive finite numbers. A target exceeding total vial mass is rejected. A calculated volume exceeding selected capacity is shown as a mismatch; the illustrative scale and copy action are disabled.
Calculation uses browser floating-point arithmetic. Results display up to six decimal places, with scientific notation for very small values. Physical device precision is a separate limit; results are not rounded to actual syringe graduations.
Examples and review
The default form is explicitly marked as an example. It is not a dose recommendation. The formula can be expanded next to the result so that each unit conversion can be checked.
The initial implementation includes automated arithmetic and input-boundary checks. No independent clinical review is claimed. Corrections to formulas or input behavior are recorded with the source code.