Peptide Reconstitution Calculator

Reconstituting a lyophilized peptide means adding a known volume of bacteriostatic water to a vial containing a known mass of peptide. That gives you a concentration. This calculator turns your vial size, reconstitution solution volume, and a dose you already have in mind into a syringe draw 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.
Doses per vial = how many times that dose divides evenly into the whole vial.

How to calculate peptide reconstitution

Read the total peptide mass printed on your vial's label — for example, 10 mg.
Note the volume of reconstitution solution (bacteriostatic or sterile water) you added, in mL.
Divide the peptide mass by that volume to get the concentration, in mg/mL.
Use that concentration to convert any dose into an injection volume — see the peptide dosage calculator for that next step.

Worked example: a 10 mg vial reconstituted with 2 mL of solution has a concentration of 10 ÷ 2 = 5 mg/mL.

Peptide reconstitution chart

Example vial-amount and water-volume combinations and the concentration each produces. This is a reference for the arithmetic only — use the calculator above with your own vial's actual amount and the water volume you add.

Vial amount	Water added	Concentration
5 mg	1 mL	5 mg/mL
5 mg	2 mL	2.5 mg/mL
5 mg	3 mL	1.67 mg/mL
10 mg	1 mL	10 mg/mL
10 mg	2 mL	5 mg/mL
10 mg	3 mL	3.33 mg/mL

How much bacteriostatic water for a peptide?

The water you add is what sets your vial's concentration — there's no single correct volume. Less water means each dose takes a smaller injection volume; more water means a larger one, at a lower concentration. Enter your vial's mg and your chosen water volume above to see the result.

Peptide units calculator

Units are the IU markings printed on a U-100 insulin syringe, where 1 mL equals 100 units. Once this calculator has your vial's concentration, it converts your injection volume into that unit scale automatically, so you read a whole number off the syringe barrel instead of a fraction of a milliliter.

Frequently asked questions

What is a peptide reconstitution calculator?

A peptide reconstitution calculator works out a vial's concentration from two numbers: the peptide amount printed on the label, and the volume of reconstitution solution you added. Once it has that concentration, it can convert any dose into an injection volume and syringe unit count.

What counts as a reconstitution solution?

Reconstitution solution usually means bacteriostatic water or sterile water — a liquid added to a lyophilized (freeze-dried) peptide vial to dissolve it into something you can measure and draw into a syringe. This calculator uses whatever volume of solution you enter; it does not recommend which solution or how much to use.

How much reconstitution solution should I add?

That depends on your vial size and the concentration you want to end up with — more solution means a lower concentration, less solution means a higher one. This calculator shows you the resulting concentration for whatever volume you enter; it does not pick an amount for you.

How do I calculate peptide reconstitution?

Divide the total peptide mass printed on the vial label by the volume of reconstitution solution you added — that gives you the concentration in mg/mL. This calculator does that division for you the moment you enter both numbers.

Is there a peptide reconstitution chart?

See the chart below for example vial-amount and water-volume combinations and the concentration each produces. It's a reference for the arithmetic only — always confirm the result for your own vial using the calculator above, since actual label amounts vary by supplier.

How do I calculate doses per vial?

Doses per vial is the total peptide amount divided by your dose, rounded down to a whole number — how many times that dose divides evenly into the vial before it runs out. The calculator above computes this automatically once you enter a dose.

How do I calculate peptide dosage after reconstitution?

Once you have your vial's concentration from reconstitution, divide your dose by that concentration to get an injection volume, then multiply by 100 to read it in units on a U-100 syringe. The peptide dosage calculator does this same math with fields tailored to a dose you already have.

What makes a good peptide reconstitution calculator?

One that shows its formula rather than hiding it, states when that formula was last verified, and doesn't send your numbers anywhere. This calculator publishes its formula above, lists a verification date, and runs entirely in your browser.

Is a "reconstitute peptides calculator" the same as this one?

Yes — "reconstitute peptides calculator," "reconstituting peptides calculator," and "peptide dosage reconstitution calculator" all describe the same kind of tool: turning a vial's peptide amount and solution volume into a concentration and, from there, a dose into a syringe draw.

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

This reconstitution calculator focuses on working out a vial's concentration from its amount and solution volume. The peptide dosage calculator starts from that same concentration and focuses on converting a specific dose into a syringe draw.

How do I reconstitute a 40 mg peptide vial?

The same way as any other size: divide the 40 mg on the label by the volume of bacteriostatic or sterile water you add, in mL, to get the concentration. For example, 40 mg reconstituted with 2 mL gives 20 mg/mL; with 4 mL it gives 10 mg/mL. Enter 40 as the peptide amount above along with your chosen water volume to get the exact concentration and, once you add a dose, the syringe draw.

Is this peptide reconstitution calculator medical advice?

No. It applies one formula — mass divided by volume, then dose divided by concentration — to the numbers you enter. It does not suggest a dose, a solution volume, 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.