What this tool does
Concentration problems come in two directions. Sometimes you know the amount and the volume and want the concentration. Other times you know the amount and the concentration written on a label and want to check the volume that goes with it. This page handles the second direction.
Inputs and outputs
- Inputs: an amount (mg, mcg, g or IU) and a target concentration (mg/mL, mcg/mL, g/L or IU/mL).
- Outputs: the volume in mL, µL and L, the steps, and a syringe-scale illustration of that liquid volume.
Formula
Volume = Amount ÷ Concentration
Generic example. 20 mg with a target of 5 mg/mL gives 20 ÷ 5 = 4 mL. With mixed units, convert first: 5,000 mcg with a target of 2.5 mg/mL becomes 5 mg ÷ 2.5 mg/mL = 2 mL.
Limitations
- The result assumes the volume is the final volume of the solution.
- The tool does not know your product. Official labeling decides which liquid and what volume apply.
- It never converts IU to mass.
Common mistakes
- Typing a target in mcg/mL while thinking in mg/mL (a thousand-fold error).
- Using the amount of one product with the concentration of another.
- Reading the result in mL when it is shown in µL.