Calculator
Bacteriostatic Water Calculator
Work backwards from what you want. Enter your vial size and either a target concentration, or a dose plus the number of units you want it to read — and get how much bacteriostatic water to add.
Enter your numbers and press Calculate — the result appears here.
How it's calculated
- For a target concentration: water mL = vial mg ÷ target concentration mg/mL
- For target units: water mL = vial mcg × target units ÷ (dose mcg × syringe units per mL)
Worked example — A 5 mg vial to 2.5 mg/mL needs 5 ÷ 2.5 = 2 mL. To make a 250 mcg dose read 10 units on a U-100 syringe also needs 2 mL.
Frequently asked questions
How much bacteriostatic water do I add to a peptide vial?
It depends on the concentration you want. Water in mL equals the vial amount in mg divided by your target concentration in mg/mL. A 5 mg vial at 2.5 mg/mL needs 2 mL.
How do I pick a water amount so my dose is an easy number of units?
Enter your dose and the units you want it to read. The calculator solves for the water that makes that true on your syringe, so the draw lands on a clean mark.
Does more bacteriostatic water weaken the peptide?
No. Water changes only the concentration, not the total peptide. More water means a lower concentration and more units per dose, not less peptide.
Is this BAC water calculator medical advice?
For informational and educational purposes only. Not medical advice. Peptides are sold for research use only. Consult a licensed healthcare professional before use.
For informational and educational purposes only. Not medical advice. Peptides are sold for research use only. Consult a licensed healthcare professional before use.