For laboratory research use only. Not for human or veterinary use. This tool performs arithmetic only.

Reconstitution Calculator

Enter the peptide amount, the volume of bacteriostatic or sterile water added and a target amount. Results update instantly: concentration, volume, U-100 syringe units and draws per vial.

1 Inputs

Peptide amount in vial

Bacteriostatic / sterile water added

Syringe type (U-100 insulin syringe)
Target amount to draw

2 Results

Syringe fill diagram
    Volume to draw
    – units– mL
    Concentration
    – mg/mL– mcg/mL
    Per 0.1 mL
    – mcg
    Per 1 unit (0.01 mL)
    – mcg
    Draws per vial
    –
    Total in vial
    – mcg
    Unit reference table for this syringe
    UnitsVolume (mL)Amount (mcg)

    How the calculation works

    The dissolved solid is assumed to add negligible volume, so the final solution volume equals the water added. All masses are converted to micrograms (1 mg = 1,000 mcg).

    1. ConcentrationC (mcg/mL) = peptide (mcg) ÷ water (mL)C (mg/mL) = C (mcg/mL) ÷ 1000
    2. Amount per graduationmcg per 0.1 mL = C × 0.1mcg per unit = C ÷ 100
    3. Volume for the targetV (mL) = target (mcg) ÷ C (mcg/mL)units = V (mL) × 100
    4. Draws per vialdraws = ⌊ peptide (mcg) ÷ target (mcg) ⌋

    Worked example

    10 mg in 2 mL → 10,000 ÷ 2 = 5,000 mcg/mL (5 mg/mL), i.e. 50 mcg per unit. A 250 mcg target → 250 ÷ 5,000 = 0.05 mL = 5 units, giving 40 draws per vial.

    FAQ

    Does the volume of water change the amount of peptide in the vial?

    No. The total mass in the vial stays the same. Adding more water lowers the concentration, so a larger volume is needed for the same target amount; adding less water raises the concentration.

    What is a “unit” on a U-100 syringe?

    U-100 syringes are graduated so that 100 units equal 1 mL. One unit is therefore 0.01 mL, and units = volume in mL × 100.

    How do mg and mcg relate?

    1 mg = 1,000 mcg (micrograms). The calculator converts everything to mcg internally, so you can enter either unit.

    Why does it warn that the volume exceeds the syringe capacity?

    The computed volume is larger than the syringe can hold (30, 50 or 100 units). Choose a larger syringe, a smaller target amount, or a higher concentration by adding less water.