The mg/mL formula
Milligrams per millilitre describe concentration: the amount of substance contained in each millilitre of liquid.
mg/mL = total milligrams ÷ total millilitres
Mathematical example:
A labelled total of 10 mg in a final volume of 2 mL has a concentration of 5 mg/mL.
Finding liquid volume from an intended amount
mL required = intended amount in mg ÷ concentration in mg/mL
PeppyCalc combines these two steps and then converts the resulting millilitres into U-100 syringe units.
Common mistakes
- Entering micrograms as though they were milligrams.
- Using the vial's physical capacity instead of the actual final liquid volume.
- Moving a decimal point when copying a value.
- Assuming all syringes use the same unit scale.