peptidevial calc. Free to use

Peptide reconstitution calculator

Still powder? See the water amount for your mix and the syringe amount for each injection.

Just converting syringe units and mL?

1 Amount for one injection

2 What’s in your vial?

3 Check your syringes

Mixing: 3 mL syringe (most common)
Injection: U-100 · 1 mL / 100 units

Change syringes

Use the smallest marked step in mL.

Check the selected lines against your syringe. On U-100, 100 units = 1 mL.

4 Water for the whole vial

Have a water amount from your mixing directions? Enter it below. Otherwise, compare options to see how the syringe amount changes.

Add a vial-volume limit
mL

Use the limit from your product or vial directions. Mixing syringe size does not tell us the vial capacity.

Enter a water amount instead
mL

Enter an amount to calculate directly, or leave blank to compare options.

No dose presets. Nothing saved.

Mixing amount & syringe draw

U-100 · 1 mL

Your mix will appear here.

Enter your target dose, vial amount, and the line spacing of both syringes to compare water amounts.

Calculates the amounts you enter. It doesn’t select a dose or check the product. How the math works

How much bacteriostatic water do I need?

The vial’s mg amount alone does not determine one water amount. Adding more water lowers the concentration, so the same target dose requires a larger draw. This bacteriostatic water calculator, sometimes called a BAC water calculator, lets you compare that relationship before selecting an amount from your product’s mixing directions.

Have a particular draw in mind? Choose a syringe draw instead to calculate the total volume after mixing. Already added the water? Calculate the draw from your mixed vial. If another calculator gives a different answer, compare the concentrations it used.

How the water comparison works

  1. Enter your numbers. Start with your target dose and the amount of peptide in the full vial.
  2. Check your syringes. Confirm their sizes and the spacing between printed lines.
  3. Read the two amounts. Water in mL is for the whole vial. The U-100 draw is for one injection. Select a different water option to see how the draw changes.

“Easy to measure” highlights a measurement preference based on the syringe settings. It does not establish product compatibility or a recommended mixture. Use your product’s directions for the appropriate liquid and amount. If those directions give a limit, enter it under “Maximum water for this vial” to filter the options.

The mixing syringe starts at 3 mL capacity, and the injection syringe starts at U-100, 1 mL (100 units), with 1-unit lines. Both settings are editable. Fractional draws still calculate without changing the default. A 3 mL mixing syringe does not establish your vial’s capacity or mean you should add 3 mL of water.

Why water amount changes your syringe draw

For a hypothetical 10 mg vial and an entered target of 0.5 mg, using 1 mL as the volume estimate gives a 0.05 mL draw (5 U-100 units). Using 2 mL gives a 0.1 mL draw (10 units). The target mass is the same; the liquid volume changes. These examples explain dilution, not which dose or water amount to use.

Water added versus final mixed volume

Water-based results assume the selected water amount equals the final mixed volume, so concentration and draw are estimates. A hypothetical 10 mg vial split into 20 equal injections contains 0.5 mg per injection. With 2 mL of water used as the volume estimate, each draw is 0.1 mL, or 10 U-100 units. These are example inputs, not a suggested dose or mixture.

To work backward from a specific draw, open “Choose a syringe draw instead.” That calculation returns the total volume after mixing; it is not automatically the amount of water to add. Once mixed, use the peptide dose calculator with the water amount you added, or use the labeled concentration when available. Read the peptide reconstitution formulas for both approaches, or see the U-100 units-to-mL chart.