When you reconstitute a lyophilised peptide, the maths behind it is simple – but it’s easy to make a small error that throws off your numbers. This calculator handles the conversions for you: enter your vial size and diluent volume to get a concentration, then convert that into a volume or syringe reading.
It’s built for one job – concentration and volume mathematics – and nothing else. It won’t tell you how much of anything to use for any purpose; that’s a research decision that sits outside what a calculator can or should determine.
Lab tool · Peptician
Concentration & Volume Calculator
Work out the concentration of a reconstituted vial, and how much volume corresponds to a given mass. For in vitro laboratory research use only.
Calculated values
Concentration
Net peptide mass in vial
Mass at selected volume
Equivalent on syringe scale
This tool performs general concentration and volume mathematics only. It does not provide, suggest, or imply a sample size, dose, or usage amount for any compound or purpose.
How to use it
1. Enter your vial content and diluent volume. Add the peptide mass stated on your vial (in mg) and how much diluent you’re adding (in mL). The calculator returns the resulting concentration in mg/mL instantly.
2. Add net peptide content, if you have it (optional). Some Certificates of Analysis state a “net peptide content” percentage – this accounts for non-peptide material (counter-ions, moisture, excipients) that can be part of a vial’s total stated weight. If you enter this figure, the calculator will use it to refine your concentration, rather than assuming the full vial weight is active peptide. Not sure where to find this? Our guide to interpreting a Certificate of Analysis explains what to look for.
3. Choose your syringe scale. Select 0.3 mL, 0.5 mL, or 1 mL to match the syringe you’re working with. This sets the reference scale for the graduated unit (IU) conversion and flags if a volume you’ve entered won’t fit.
4. Enter a volume or a unit reading – whichever you have. You can work from either direction: enter a volume in mL to see the equivalent graduated units, or enter a unit reading to see the equivalent volume. The two stay in sync automatically, so there’s no need to convert by hand.
5. Read your results. The results panel shows your concentration, the net peptide mass in the vial, the mass corresponding to your selected volume (in mcg), and the equivalent graduated unit reading. If your chosen volume exceeds the capacity of the selected syringe, you’ll see a warning so you can adjust before recording anything.
A note on accuracy
This tool is designed to remove arithmetic error, not judgement. Always:
- Cross-check the vial mass and diluent volume against your own records before relying on a result
- Use net peptide content from your CoA where available, since total vial weight alone can overstate actual peptide content
- Treat this as a calculation aid for your research records, not a substitute for your own verification
For the full reconstitution process – including diluent selection, sterile technique, and handling the vial correctly – see our step-by-step reconstitution guide.