Peptide Dosage Calculator

If you already know the dose you need to take, this calculator converts it into a syringe draw. It works out your vial's concentration from the peptide amount and bacteriostatic water you entered, then divides your dose — in mg or mcg — by that concentration to get an injection volume and unit count.

Peptide amount in vial

The total peptide mass printed on your vial label.

mgmcg

Bacteriostatic water added

How much water you added to reconstitute the vial.

Desired dose

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

mgmcg

Syringe size (U-100)

0.3 mL0.5 mL1.0 mL

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: —

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.

Worked example: a 5 mg vial reconstituted with 2 mL of bacteriostatic 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.

Calculating peptide dosage after reconstitution

Before reconstitution, a vial only has a total mass printed on its label — for example, “10 mg.” Once you add water, that mass is spread through a known volume, which gives you a concentration. Every dose calculation after that point depends on this number. To calculate dosage after reconstitution: confirm the exact water volume you added, divide the peptide mass by that volume to get the concentration, then divide your dose by the concentration to get the injection volume.

Peptide dosage in mg vs. mcg

Vial labels and protocols mix units — some use milligrams (mg), others micrograms (mcg). 1 mg = 1,000 mcg. Entering a value in the wrong unit is a common source of a thousand-fold error, so match whichever unit is printed on your paperwork exactly. The calculator above has an mg/mcg toggle for both the vial amount and the dose field.

Peptide dosing chart: unit conversions

This chart converts between units only — it is not a recommended dose for any compound. Your prescribed or protocol dose comes from your own paperwork, not this chart.

mg to mcg
mg	mcg
0.1 mg	100 mcg
0.25 mg	250 mcg
0.5 mg	500 mcg
1 mg	1,000 mcg
2 mg	2,000 mcg
5 mg	5,000 mcg
10 mg	10,000 mcg

mL to U-100 syringe units
mL	Units
0.05 mL	5 units
0.1 mL	10 units
0.2 mL	20 units
0.25 mL	25 units
0.5 mL	50 units
0.75 mL	75 units
1.0 mL	100 units

How much bacteriostatic water for a peptide?

Bacteriostatic water isn't dosed itself — it only sets the concentration your peptide dissolves into. Adding more water lowers that concentration, which means a larger injection volume for the same dose; adding less raises it, for a smaller volume. Enter your vial's mg and water volume above, then your dose, to see the volume it produces.

Peptide units calculator

A U-100 insulin syringe is marked in units, not milliliters — 100 units per mL. Once you've entered your dose, this calculator translates the injection volume it calculates into that same unit scale, so you can draw to a printed line on the barrel rather than estimating a fraction of a milliliter.

Frequently asked questions

What is a peptide dosage calculator?

A peptide dosage calculator converts a dose you already have — in mg or mcg — into an injection volume and syringe unit count. It works out your vial's concentration from the peptide amount and water you added, then divides your dose by that concentration. It performs a fixed arithmetic conversion; it does not choose or recommend a dose.

How do I calculate peptide dosage in mg?

First find your vial's concentration by dividing the total peptide mass on the label (in mg) by the volume of bacteriostatic or sterile water you added (in mL). Then divide your dose in mg by that concentration to get the injection volume in mL. Multiply the volume by 100 to read it in units on a U-100 syringe.

How do I calculate peptide dosage after reconstitution?

Once a vial is reconstituted, its concentration is fixed at peptide mass divided by the water volume you added. Divide your dose by that concentration to get the volume to draw. If the same vial is reconstituted again with a different amount of water, the concentration — and the volume for the same dose — changes accordingly.

How many syringe units is my dose?

Multiply your injection volume in mL by 100, since a standard U-100 insulin syringe holds 100 units per mL. For example, an injection volume of 0.1 mL is 10 units.

What's the difference between a dosage calculator and a reconstitution calculator?

A peptide reconstitution calculator works out a vial's concentration from the peptide amount and water added. This dosage calculator takes that same concentration one step further and converts a specific dose into an injection volume and syringe unit count.

Is "peptide dosages" the same thing this calculator computes?

Yes. "Peptide dosages" is just the plural of "peptide dosage" — the injection volume and unit count this calculator produces for each dose you enter.

Is this the same as a peptide dosing calculator?

Yes — "dosing" and "dosage" are used interchangeably here. Both describe converting a dose you already have into an injection volume and syringe unit count.

Are there different peptide dosage calculators for different compounds?

This page handles any peptide with the same underlying math. There are also compound-specific dosage calculators — for BPC-157, semaglutide, tirzepatide, and others — that pre-fill typical vial sizes for that compound, but they all compute the same concentration-then-dose arithmetic as this page.

Can I use mg with this peptide calculator?

Yes. Both the vial amount and the dose field have an mg/mcg toggle, so you can enter a peptide amount in mg (or switch to mcg) and get the same injection volume and unit count either way — just make sure the toggle matches the unit printed on your vial or prescription.

Is there a peptide calculator app?

This site works as a web app — no download required. On a phone, you can add it to your home screen from your browser's share menu for one-tap access, and it works the same as any native peptide calculator app since all the math runs locally in your browser.

What is peptide dosage?

Peptide dosage is the amount of peptide — in mg or mcg — you take in a single injection. Once a vial is reconstituted, that dosage corresponds to a specific injection volume and syringe unit count, which is exactly what this calculator works out for you.

How do I use this peptide calculator to find my dose in mL or units?

Enter your vial's peptide amount and the water volume you added, then enter your dose. The calculator returns that dose as both an injection volume in mL and a unit count on a U-100 syringe, so you can measure it whichever way your syringe is marked.

Is this peptide dosage calculator medical advice?

No. It applies one formula — dose divided by concentration, times 100 — to the numbers you enter. It does not suggest a dose, a starting point, or a typical amount for any compound. See the medical disclaimer for full detail.

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