# Peptide Reconstitution Calculator > Interactive tool: https://peptpedia.org/peptide-reconstitution-calculator > Pre-filled links via query parameters: ?vial=&water=&dose=&syringe=<30|50|100> > Backward mode (solve diluent volume): ?mode=backward&vial=&dose=&units= Free calculator for reconstituting lyophilized research peptides. Given the vial mass, the diluent volume (e.g. bacteriostatic water), and a target amount per dose, it returns the solution concentration, the exact draw volume in mL and U-100 insulin syringe units, and the number of doses per vial — with warnings for impractical draws (under 5 units), syringe overflow, and over-volume vials. ## Formulas - Concentration (mcg/mL) = vial mass (mg) × 1,000 ÷ diluent volume (mL) - Draw volume (mL) = target amount (mcg) ÷ concentration (mcg/mL) - Syringe units (U-100) = draw volume (mL) × 100 - Doses per vial = vial mass (mcg) ÷ target amount (mcg) - Diluent for a target draw (mL) = vial mass (mcg) × target draw (mL) ÷ target amount (mcg) ## Worked example 5 mg vial + 2 mL bacteriostatic water → 2,500 mcg/mL. A 250 mcg target amount → 0.1 mL = 10 units on a U-100 syringe; 20 doses per vial. Pre-filled: https://peptpedia.org/peptide-reconstitution-calculator?vial=5&water=2&dose=250 ## Accuracy notes - Draws under ~5 units are difficult to measure accurately on a U-100 syringe — add more diluent. - Standard research vials hold ~3 mL; larger diluent volumes need a bigger vessel. - Vial contents include water and counterions; exact quantitative work applies the net peptide content correction from the batch certificate of analysis. For laboratory research calculations only. Not medical advice; not guidance for human or veterinary use. Full context: https://peptpedia.org/peptide-reconstitution