Laboratory concentration calculator
Work out the concentration of a stock solution from a starting mass and a final solution volume, the volume of solution that holds a chosen laboratory aliquot mass, or the stock and diluent volumes for a dilution. Every calculation happens in your browser. Nothing you type leaves your device or is sent to analytics.
How the math works
Each result shows the formula with your numbers substituted, so you can check every step.
- Stock concentration: concentration = mass ÷ final solution volume. Example: 8 mg ÷ 4 mL = 2 mg/mL = 2000 µg/mL.
- Aliquot volume: aliquot volume = aliquot mass ÷ stock concentration. Example: at 2 mg/mL, 500 µg (0.5 mg) ÷ 2 mg/mL = 0.25 mL.
- Dilution: C1V1 = C2V2. Example: stock 2 mg/mL, target 0.5 mg/mL, target volume 10 mL. Stock volume = (0.5 × 10) ÷ 2 = 2.5 mL. Diluent = 10 - 2.5 = 7.5 mL.
Units and conversions
Mass: 1 g = 1000 mg, 1 mg = 1000 µg, 1 oz = 28.349523125 g. Volume: 1 L = 1000 mL, 1 fl oz = 29.5735295625 mL. You can type decimals with a point or a comma (1.5 or 1,5).
Switching the unit label keeps the number you typed and reinterprets it in the new unit. To convert the same quantity into the new unit instead, use the Convert button.
What this tool does not do
- It does not determine a personal amount of anything.
- It does not give instructions for preparing or using a solution.
- It says nothing about solubility, stability, or suitability for human use.
- It never suggests a compound, a supplier, or a course of action.