Laboratory Tool
Peptide Reconstitution Calculator
A free peptide reconstitution calculator for qualified laboratory researchers. Enter the peptide amount in your vial (mg) and the volume of bacteriostatic water you plan to add (mL), and instantly see the resulting concentration (mg/mL) - plus a micrograms-per-0.1 mL volumetric reference for fine research measurements.
For Research Use Only. Not for human or veterinary use. Not a drug, food, or cosmetic. This calculator is for concentration reference in qualified laboratory settings and does not provide dosing, administration, or medical guidance.
Calculated concentration
Enter a peptide amount and diluent volume to see the concentration.
Common examples
How to Use This Calculator
- Find the total peptide mass printed on your vial label or Certificate of Analysis (e.g. 5 mg or 10 mg) and enter it in the first field.
- Decide how much bacteriostatic or sterile water you will add to the vial, and enter that volume in milliliters.
- Read the calculated concentration in mg/mL - updated live as you type - along with the µg per 0.1 mL reference.
- Adjust the water volume up or down to compare concentrations before you reconstitute, or click a common example to populate the inputs instantly.
How Peptide Reconstitution Concentration Is Calculated
Reconstitution means dissolving a lyophilized (freeze-dried) peptide in a measured volume of diluent. The arithmetic is a simple ratio:
Concentration (mg/mL) = peptide (mg) ÷ water (mL)
Adding less bacteriostatic water yields a more concentrated solution; adding more water dilutes it. The total peptide mass never changes - only the volume it is distributed across. For a full walkthrough of laboratory reconstitution handling, storage, and solution-tracking best practices, see our peptide reconstitution guide.
Common Reconstitution Examples
| Peptide amount | Water added | Concentration |
|---|---|---|
| 5 mg | 1 mL | 5 mg/mL |
| 5 mg | 2 mL | 2.5 mg/mL |
| 10 mg | 2 mL | 5 mg/mL |
| 10 mg | 5 mL | 2 mg/mL |
Reconstitution Calculator FAQ
Enter the total peptide mass printed on your vial (in milligrams) and the volume of diluent you plan to add (in milliliters). The calculator divides the mass by the volume and displays the resulting concentration in mg/mL, plus a micrograms-per-0.1 mL research reference. You can then measure any working volume against that concentration in your laboratory workflow.
That depends on the concentration your research protocol calls for. Adding less water produces a more concentrated solution; adding more water dilutes it. For example, a 10 mg vial reconstituted with 2 mL of bacteriostatic water yields 5 mg/mL, while the same vial with 5 mL yields 2 mg/mL. Use the common examples table on this page to see how volume changes concentration.
Divide the peptide mass (mg) by the total liquid volume (mL): Concentration (mg/mL) = peptide (mg) ÷ water (mL). A 5 mg vial dissolved in 2 mL gives 2.5 mg/mL. This calculator performs the same arithmetic instantly and also converts the result to micrograms per 0.1 mL for fine volumetric reference.
mg/mL (milligrams per milliliter) expresses how much peptide mass is dissolved in each milliliter of solution. A concentration of 2.5 mg/mL means every 1 mL of the reconstituted solution contains 2.5 mg of peptide - equivalently 250 µg per 0.1 mL. It is the standard unit for tracking solution strength in laboratory peptide handling.
No. Bacteriostatic water for injection (BWFI) is sterile water containing 0.9% benzyl alcohol, a preservative that inhibits bacterial growth after the vial seal is punctured, making it suitable for multi-use laboratory reconstitution. Plain sterile water contains no preservative and is intended for single-use applications. Both serve as diluents in research settings, but bacteriostatic water is the common choice for reconstituting lyophilized research peptides.
For Research Use Only. Not for human or veterinary use. Not a drug, food, or cosmetic. This page is educational reference material for qualified researchers and contains no medical advice, dosing, or health claims.