Enter your syringe size, vial strength, water added, and target dose, get the exact syringe unit to draw to, instantly and free.
This only labels your calculation with a peptide name, for your own reference. It does not fill in, choose, or suggest any values. Enter your syringe, vial strength, water, and dose yourself below, based on your own supplies.
Labeled as . This is a label only, please still fill in steps 1 to 4 yourself using your own vial and syringe.
Choose the barrel size printed on your syringe. It sets the unit scale (a U-100 syringe always reads 100 units per full mL, whatever its size).
This is the total amount of peptide (in mg) freeze-dried inside the vial, printed on the label or certificate of analysis.
The volume of solvent you mix into the vial. More water means a more dilute solution; less water means a more concentrated one.
The amount (in mcg) you intend to draw per injection. The calculator instantly tells you where to stop pulling the plunger.
To get a dose of 100 mcg, pull the syringe to
0units
The calculator only ever needs these four inputs. Here's what each one means and where to find it.
Choose the barrel size printed on your syringe. It sets the unit scale (a U-100 syringe always reads 100 units per full mL, whatever its size).
This is the total amount of peptide (in mg) freeze-dried inside the vial, printed on the label or certificate of analysis.
The volume of solvent you mix into the vial. More water means a more dilute solution; less water means a more concentrated one.
The amount (in mcg) you intend to draw per injection. The calculator instantly tells you where to stop pulling the plunger.
units to draw = (dose mcg ÷ ((vial mg × 1000) ÷ water mL)) × 100
Every part of this was built the way a real internal lab tool would be, not just a quick demo.
Every figure is computed live from your inputs with full-precision math, no lookup tables, no rounding guesswork.
Nothing you type is stored or sent anywhere for tracking. Calculations happen locally the instant you click.
A second, independent PHP calculation quietly double-checks every result so the number on screen is never a guess.
From a phone at the lab bench to a widescreen monitor at a desk, the layout adapts without losing precision.
If a dose won't physically fit your chosen syringe, you'll see a clear warning before you draw anything.
A comfortable reading experience at the bench or at a desk, whatever the lighting.
No prior background assumed, this is the short version of everything the calculator is doing for you.
Peptides are usually shipped as a freeze-dried powder inside a small glass vial, because powder is far more stable than liquid. Reconstitution is simply mixing that powder with a liquid, almost always bacteriostatic water, so it becomes a solution you can measure and draw into a syringe.
Once the powder is dissolved, the peptide is spread evenly through the liquid. How "strong" that liquid is, its concentration, depends entirely on how much water you added to how much powder. The same vial can be made more dilute or more concentrated just by changing the water volume.
Insulin-style syringes aren't marked in millilitres, they're marked in units, following the U-100 standard where 100 units always equals exactly 1 mL. Once you know the concentration and the dose you want, the calculator works out the matching volume, then converts that volume into the unit mark to pull to on your specific syringe.
Mixing up mg and mcg. Vial strength is in milligrams; doses are usually in micrograms, a 1,000× difference that's easy to slip on by hand.
Assuming every syringe reads the same. A 0.3 mL, 0.5 mL, and 1 mL syringe all use the same 100-units-per-mL scale, but their maximum capacity is very different.
Forgetting to re-check after changing water volume. Every time you reconstitute with a different amount of water, the concentration, and therefore the correct unit mark, changes too.
Not noticing a dose doesn't fit. A calculated volume can exceed what a small syringe can physically hold; the warning banner above exists specifically to catch this.
Can't find yours? The explanations above in "Learn" cover the underlying concepts in more depth.
Insulin-style syringes are marked in "units" rather than millilitres, following the U-100 standard: a full 1 mL syringe always equals 100 units, so 0.5 mL equals 50 units and 0.3 mL equals 30 units, regardless of the barrel's physical size. This calculator converts your target dose straight into that unit scale.
Concentration is simply the total peptide mass divided by the total liquid volume: (vial strength in mg × 1000) ÷ bacteriostatic water in mL gives you micrograms per millilitre. Everything else, volume needed, units to draw, follows from that one number.
Every syringe has a maximum volume it can hold. If the volume required to deliver your target dose is larger than that maximum, the dose physically won't fit in one draw. You can fix this by using less bacteriostatic water (which concentrates the solution, so less volume is needed per dose), choosing a larger syringe, or lowering the target dose.
More bacteriostatic water dilutes the peptide, so the same dose requires drawing a larger volume, useful for very small, precise doses. Less water concentrates the peptide, so the same dose takes up less volume, useful when you need to fit a large dose into a small syringe.
No. This tool performs arithmetic based on numbers you provide; it doesn't know what substance you're working with, its intended use, or your specific research protocol. It's built to remove calculation error, not to offer medical, dosing, or safety advice.
Run the calculator once per peptide/vial combination. Mixing different substances in a single reconstitution changes the chemistry involved and is outside the scope of a simple volume calculator.
No. Searching and selecting a peptide only labels your calculation with its name, for your own reference. It never fills in, chooses, or suggests a vial strength, water volume, dose, or syringe size. You enter every value yourself, based on your own vial label and supplies, every time.