Enter the mg in your vial and the dose you want. The calculator gives the bacteriostatic water to add, the mg/mL, and the units to draw on a U-100 insulin syringe.
Worked example: a 5 mg vial with 2 mL of BAC water is 5 ÷ 2 = 2.5 mg/mL. A 250 mcg (0.25 mg) dose is 0.25 ÷ 2.5 = 0.1 mL, which is 10 units on a U-100 syringe. With 1 mL instead, the same dose is 5 units. The amount of water is a choice; it changes the units, not the mg in the vial. Amounts on this page are examples to show the math, not dose recommendations. How much to take is a decision for you and your prescriber.
Runs entirely in your browser; nothing you type is sent anywhere. Same planner as the peptide reconstitution calculator and the Dose Track app. Arithmetic, not medical advice.
Bacteriostatic (BAC) water does not change how much peptide is in the vial. It only decides how strong the solution is, and that decides how many units each dose takes up on the syringe. Three lines:
mg in vial ÷ mL of BAC water = mg/mLdose in mg ÷ mg/mL = mLmL × 100 on a U-100 insulin syringe (× 40 on U-40)The calculator runs this backwards: it tries every labeled 10-unit mark on the barrel and returns the water volumes that put your dose exactly on one, so the draw is easy to read.
Each row is one vial size with one water volume. The last columns are units on a U-100 syringe for example amounts, to show the math; they are not doses. "Over 100" means more than a full 1 mL syringe.
| Vial | BAC water | Concentration | Per 10 units | 250 mcg | 500 mcg | 1 mg | 2 mg |
|---|---|---|---|---|---|---|---|
| 5 mg | 1 mL | 5 mg/mL | 500 mcg | 5 | 10 | 20 | 40 |
| 2 mL | 2.5 mg/mL | 250 mcg | 10 | 20 | 40 | 80 | |
| 3 mL | 1.667 mg/mL | 166.7 mcg | 15 | 30 | 60 | over 100 | |
| 10 mg | 1 mL | 10 mg/mL | 1 mg | 2.5 | 5 | 10 | 20 |
| 2 mL | 5 mg/mL | 500 mcg | 5 | 10 | 20 | 40 | |
| 3 mL | 3.333 mg/mL | 333.3 mcg | 7.5 | 15 | 30 | 60 | |
| 15 mg | 1 mL | 15 mg/mL | 1.5 mg | 1.7 | 3.3 | 6.7 | 13.3 |
| 2 mL | 7.5 mg/mL | 750 mcg | 3.3 | 6.7 | 13.3 | 26.7 | |
| 3 mL | 5 mg/mL | 500 mcg | 5 | 10 | 20 | 40 | |
| 20 mg | 1 mL | 20 mg/mL | 2 mg | 1.3 | 2.5 | 5 | 10 |
| 2 mL | 10 mg/mL | 1 mg | 2.5 | 5 | 10 | 20 | |
| 3 mL | 6.667 mg/mL | 666.7 mcg | 3.8 | 7.5 | 15 | 30 | |
| 30 mg | 1 mL | 30 mg/mL | 3 mg | 0.8 | 1.7 | 3.3 | 6.7 |
| 2 mL | 15 mg/mL | 1.5 mg | 1.7 | 3.3 | 6.7 | 13.3 | |
| 3 mL | 10 mg/mL | 1 mg | 2.5 | 5 | 10 | 20 |
Scroll the table sideways to see every column.
Less water makes a strong solution and a small draw: 250 mcg from a 10 mg vial in 1 mL is 2.5 units, which sits between the marks. More water makes a weaker solution and a bigger, easier-to-read draw, but the vial has to hold it and each dose is more liquid. Most people pick a volume that puts their dose on a round number like 10 or 20 units, which is what the calculator looks for.
Already mixed? Switch to I already added water above and enter the volume you used. Mixing a vial with several peptides in it? Use the peptide blend calculator. Growth hormone measured in IU? Use the HGH calculator.