How the Peptide Calculator Works
The peptide calculator works by combining three simple inputs, vial strength, reconstitution volume, and target dose, to return the exact amount you need to draw into a syringe.
- Enter the peptide vial strength in milligrams (mg), as printed on the vial label.
- Enter how much bacteriostatic water you plan to add to reconstitute the peptide, in millilitres (mL).
- Enter your desired dose, in micrograms (mcg) or milligrams (mg).
- Select your syringe size, 0.3 mL, 0.5 mL, or 1 mL (U-100 insulin syringe).
Once you hit calculate, the tool instantly works out your solution's concentration (mg/mL), the number of units to draw on your syringe, and how many total doses you'll get from the vial. Because this peptide calculator is built specifically around bacteriostatic water reconstitution, the results account for standard U-100 syringe markings, so you can go straight from the screen to your workspace without converting anything by hand.
Peptide Calculator MG
Most peptide vials are labelled in milligrams, but many research protocols call for doses in micrograms, which is where a dedicated peptide calculator mg function becomes useful. Our tool automatically converts between mg and mcg, so you never have to move the decimal point by hand.
For example, a 5 mg vial contains 5,000 mcg of peptide. If your protocol calls for a 250 mcg dose, the mg-to-mcg conversion shows you exactly what fraction of the vial that represents, and how that translates into syringe units once the peptide is reconstituted. This removes one of the most common sources of dosing error: mixing up milligrams and micrograms when the vial label and the protocol use different units.
Peptide Reconstitution Calculator
Reconstitution is the process of mixing a lyophilised (freeze-dried) peptide with a liquid, almost always bacteriostatic water, to bring it into a usable solution. Get the ratio wrong, and every dose calculated afterwards will be wrong too, which is why a dedicated peptide reconstitution calculator matters as much as the dosing maths itself.
Enter your vial strength and the volume of bacteriostatic water you're adding, and the reconstitution calculator returns your solution's concentration in mg/mL. As a specialist supplier of pharmaceutical-grade bacteriostatic water, we've built this calculator around real-world volumes, 1 mL, 2 mL, 3 mL, and 5 mL, so the numbers you see match the bottle sizes you're actually working with.
New to reconstitution? Read our full step-by-step guide to reconstituting peptides before you begin.
General guideline: less water means a more concentrated (stronger) solution, and more water means a more dilute one. Neither is "correct" on its own, the right volume depends on your syringe size and how precisely you need to measure small doses.
Understanding Peptide Calculator Results
Once you've entered your numbers, the calculator returns three key results:
- Concentration (mg/mL): how much peptide is in each millilitre of your reconstituted solution.
- Units to draw: the exact mark on your syringe (based on a standard U-100 insulin syringe, where 100 units = 1 mL) that corresponds to your target dose.
- Doses per vial: how many total doses you can draw from a single vial at your chosen dose size.
If the calculator shows a warning, it usually means your target dose can't be drawn accurately on the syringe size you've selected, for example, a very small dose diluted in a large volume may fall below the smallest readable unit mark. In that case, either reduce the amount of bacteriostatic water used (creating a more concentrated solution) or switch to a smaller syringe for finer measurement.
Peptide Calculator FAQs
What is a peptide calculator?
A peptide calculator is a free tool that works out how much reconstituted peptide solution to draw into a syringe, based on your vial strength, the amount of bacteriostatic water added, and your target dose.
How do I use a peptide reconstitution calculator?
Enter your vial's peptide strength in mg, the volume of bacteriostatic water you're adding in mL, and your desired dose in mcg or mg. The calculator does the rest, returning your concentration and the exact syringe units to draw.
Why do I need to reconstitute peptides with bacteriostatic water?
Peptides are shipped as a freeze-dried powder to preserve stability during transport and storage. Bacteriostatic water, water containing 0.9% benzyl alcohol as a preservative, is used to reconstitute the peptide into a liquid solution that can be measured and drawn accurately.
What's the difference between a peptide calculator and a peptide calculator mg tool?
They're the same calculator, "mg" simply refers to the milligram inputs and conversions built into the tool, since most vials are labelled in mg while many protocols are dosed in mcg.
How much bacteriostatic water should I use to reconstitute my peptide?
It depends on your vial size and how precisely you need to dose. Common volumes are 1 mL, 2 mL, and 3 mL. Adding less water creates a more concentrated solution; adding more creates a more dilute one. See our full breakdown on how much bacteriostatic water to use by vial size, or use the reconstitution calculator above to see how each option affects your syringe units.
How long does reconstituted peptide solution last?
Once reconstituted, most peptide solutions should be stored refrigerated (around 2–8°C) and used within the timeframe stated on your product's storage guidance. Always check the specific peptide's documentation, as stability varies by compound.
Can I use this calculator for any peptide?
Yes, this calculator peptide tool works with any peptide reconstituted in bacteriostatic water, since the underlying maths (concentration, syringe units, doses per vial) is the same regardless of which compound you're using.
Is this peptide calculator a substitute for professional or clinical guidance?
No. This tool is designed for research and informational purposes to simplify reconstitution arithmetic. It does not provide medical advice, dosing recommendations, or clinical guidance, and should not be treated as a substitute for consulting a qualified professional.