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Peptide calculator

Reconstitution, BAC water, and syringe units, with every step shown.

In short
A peptide calculator turns the numbers on your vial into a mixing plan: how much bacteriostatic water to add, the concentration that makes, how many units to measure on your syringe, and how many measurements the vial gives. Enter your numbers below to see all of it, with the math.

Prefer a guided, one-question-at-a-time walkthrough? Use the guided plan builder.

1
Compound

Which peptide are you mixing?

Pick from the list, or choose “Other” if yours isn't shown.

2
Vial size

What size is your vial?

Look at your label for a number like "5 mg."

3
Amount

How much do you measure each time?

Type the amount you measure each time, in mg or mcg.

4
Syringe

Which syringe are you using?

Not sure? A 1 mL insulin syringe works for almost everyone.

Quick tip: Insulin syringes are marked in units. 100 units = 1 mL, so 10 units = 0.1 mL. We'll tell you exactly how many units to draw.
5
BAC water

How much BAC water to add?

BAC water is the sterile liquid that dissolves the powder. More water = larger, easier-to-measure draws.

6
Mixing date

When did you (or will you) mix it?

Optional. Lets us calculate when the vial expires so you know when to discard it.

Saves your plan with a shareable link, downloadable PDF, and printable vial labels.

Choose your peptide, vial amount, and the amount you measure to see your plan here.

How the peptide calculator works

Reconstitution is one division and one conversion. The calculator does both from your numbers and shows the work:

  1. 1
    Concentration

    Vial amount divided by the bacteriostatic water you add. A 5 mg vial with 2 mL of water is 2.5 mg/mL.

  2. 2
    Volume to measure

    The amount you want divided by the concentration. 250 mcg at 2.5 mg/mL is 0.1 mL.

  3. 3
    Syringe units

    On a U-100 insulin syringe, 100 units equal 1 mL, so 0.1 mL is 10 units.

  4. 4
    Measurements per vial

    The vial amount divided by the amount per measurement, so you know how long a vial lasts.

What this calculator does not decide
It calculates concentration and measurement from the numbers you enter. It does not recommend how much to use, how often, or whether a compound is safe or right for anyone. What no calculation can verify.

Calculators by compound

Each compound page has the same calculator plus its common vial sizes, storage, and what research looked at.

TirzepatideRetatrutideSemaglutideBPC-157TB-500Ipamorelin
All compounds

Peptide calculator FAQ

A peptide calculator does the reconstitution math. It turns your vial's amount and the amount you want to measure into how much bacteriostatic water to add, the concentration that makes, and how many units to draw on an insulin syringe. It calculates from your numbers, it does not recommend how much to use.

Concentration equals the vial amount divided by the bacteriostatic water you add. The volume to measure equals the amount you want divided by that concentration. On a U-100 insulin syringe, that volume times 100 gives the units. This calculator shows every step so you can check it.

Enough that your measurement lands on a clean, easy-to-read mark. The calculator suggests an amount that puts a typical measurement near 10 units on a 1 mL insulin syringe, and you can change it to any amount you prefer.

On a U-100 insulin syringe, 100 units equal 1 mL, so 0.1 mL is 10 units and 0.05 mL is 5 units. Enter your concentration and the amount you want, and the calculator converts it to exact units.

No. It calculates concentration and measurement from the numbers you enter. It does not recommend an amount, a frequency, or whether a compound is safe or suitable for anyone. Those questions are not math, and this site does not answer them.

Related tools and guides

BAC water calculatorReverse BAC water calculatorSyringe unit converterHow reconstitution worksWhat you cannot know about your vial