PeptideCalculate

Peptide Calculator

Enter the peptide amount in your vial, how much bacteriostatic water you added, and the dose you've already been told or prescribed to take. This tool converts those numbers into a concentration and a syringe draw — it does not choose a dose for you.

The total peptide mass printed on your vial label.

mL

How much water you added to reconstitute the vial.

The dose you already have — this tool converts it, it doesn't choose it for you.

Syringe size (U-100)

Results

Syringe draw

—u

Enter your dose above

Concentration (mg/mL)
2.50 mg/mL
Concentration (mcg/mL)
2,500.00 mcg/mL
Injection volume
Enter your dose above
mcg per unit
25.00 mcg
Doses per vial
—
01020304050607080901000.0u
Formula: dose ÷ concentration × 100 — see methodologyFormulas verified: July 23, 2026No data leaves your browser

Arithmetic only — this tool does not recommend a dose.

How this calculator works

  • Concentration = peptide amount ÷ bacteriostatic water volume.
  • Injection volume = your dose ÷ that concentration.
  • Syringe units = injection volume × 100, since a U-100 syringe holds 100 units per mL.

This calculator works the same way for any peptide — BPC-157, semaglutide, tirzepatide, retatrutide, or others — just enter the amount and water volume printed on your own vial.

How to calculate peptide dose

  1. Divide the peptide amount on your vial label by the water volume you added, to get the concentration in mg/mL.
  2. Divide your dose by that concentration to get an injection volume in mL.
  3. Multiply the injection volume by 100 to read it in units on a U-100 syringe.

Worked example: a 5 mg vial reconstituted with 2 mL of water has a concentration of 5 ÷ 2 = 2.5 mg/mL. A 0.25 mg dose becomes 0.25 ÷ 2.5 = 0.1 mL, or 10 units on a U-100 syringe. See the peptide dosage calculator for a mg/mcg unit conversion chart and more worked examples.

How much bacteriostatic water for a peptide?

There's no single right amount — the water you add sets the concentration. More water means a lower concentration and a larger injection volume for the same dose; less water means a higher concentration and a smaller volume. Enter your vial's mg and your chosen water volume above to see the exact concentration and syringe draw.

Peptide units calculator

"Units" refers to the IU markings on a standard U-100 insulin syringe, where 100 units equal 1 mL. This calculator converts your injection volume into that same unit scale, so instead of measuring a fraction of a milliliter, you can read your dose directly off the syringe's printed unit markings.

Frequently asked questions

What is a peptide calculator?

A peptide calculator works out the concentration of a reconstituted vial from its peptide amount and water volume, then converts a dose into an injection volume and syringe unit count. It's a fixed arithmetic tool — it does not choose a dose or a compound for you.

How do I use a peptide calculator?

Enter the peptide amount printed on your vial, the volume of bacteriostatic or sterile water you added, and the dose you already have. The calculator divides amount by water volume to get concentration, then divides your dose by that concentration to get an injection volume and unit count.

Does this peptide calculator work for any compound?

Yes. The math — concentration equals mass divided by volume — is the same regardless of which peptide is in the vial, whether that's BPC-157, semaglutide, tirzepatide, retatrutide, or any other compound. Only the label amount and water volume you enter change from one vial to the next.

How do I calculate peptide dose?

Divide your dose by the vial's concentration to get an injection volume, then multiply by 100 to read it in units on a U-100 syringe. Find the concentration first by dividing the peptide amount on the vial label by the water volume you added — the calculator above does this for you.

Is a peptide calc the same as this peptide calculator?

Yes — "peptide calc," "peptide dosing calculator," and "peptide dosage calculator" all refer to the same kind of tool: converting a vial's amount and water volume into a concentration, then a dose into a syringe draw.

Is a "peptides calculator" the same as a peptide calculator?

Yes — singular or plural, "peptide calculator" and "peptides calculator" describe the same kind of tool. This one covers both reconstitution (vial amount and water volume into a concentration) and dosage (a dose into a syringe draw) in a single page.

Is this peptide calculator free and private?

Yes. It runs entirely in your browser — the numbers you enter are never sent anywhere or stored. There's no account, no login, and no data leaves your device.

Is this peptide calculator medical advice?

No. It performs arithmetic on the numbers you provide and does not suggest a dose, a starting point, or a typical amount for any compound. See the medical disclaimer for full detail.

Is a peptide mixing calculator the same as this peptide calculator?

Yes — "peptide mixing calculator" and "reconstitute peptides calculator" both describe the same task this tool performs: turning a vial's peptide amount and the water you mix in into a concentration, then a dose into a syringe draw.

Is this a peptide bac water calculator?

Yes. Bacteriostatic (bac) water is the diluent most vials call for, and its volume is exactly the number this calculator uses to work out concentration — enter your peptide amount and the bac water volume you added to see the result.

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Educational tool only, not medical advice — verify with a licensed clinician. See the full medical disclaimer.