Enter the vial size, liquid amount and target dose to calculate draw volume and syringe units. The tool is free, runs in your browser, and does not save your numbers. New to reconstitution? Read the Peptide Education guide first. For cost or run-out math, use the Run-Out & Cost Planner.
Dose calculator
This tool runs in your browser. Your numbers are not saved or sent.
Enter each compound's own mg content — the vial total below is the sum of these.
Enter the dose you want — see the draw volume and syringe units to pull.
Live draw volume
Example conversion table
Mathematical examples based only on the vial size, liquid amount and syringe type entered above. These rows are not suggested amounts.
Dose
Draw Volume
Syringe Units
How to Use This Calculator
Enter the values from the label and the amount you plan to draw.
Enter your vial size and BAC waterCheck your vial label for total mg (or mcg) of peptide, and confirm how much bacteriostatic water you're adding.
Choose a calculation mode"Target a dose" if you know the dose you want and need the draw volume; "I know my draw" if you already know what you're drawing and want to see the dose it delivers.
Enter your dose (or draw amount) and syringe typeMatch your syringe selection to what you're actually using — U-100 and U-40 insulin syringes read differently for the same volume.
Read your results and the live syringe visualThe draw volume, syringe units, doses-per-vial and cost-per-dose all update instantly, along with a visual fill level so you can sanity-check the reading.
How the Math Works
Standard pharmaceutical reconstitution arithmetic — the same calculation a pharmacist performs when reconstituting a lyophilized vial.
Concentration. Concentration (mg/mL) = total peptide in the vial (mg) ÷ bacteriostatic water added (mL). Standard reconstitution arithmetic.
Draw volume. Draw volume (mL) = desired dose ÷ concentration, with unit conversions handled automatically between mg and mcg (1 mg = 1,000 mcg). SI unit definitions, BIPM.
Syringe units. Syringe units = draw volume (mL) × the syringe's units-per-mL rating — 100 for a U-100 syringe, 40 for a U-40 syringe, fixed by syringe manufacturing standards. ISO 7864 syringe graduation standards.
Blends. For a multi-compound blend, each component's share of a given draw is calculated proportionally to its share of the vial's total mg content. Proportional allocation, standard for multi-component solutions.
Estimate only — not medical advice. This tool performs unit conversion and arithmetic based on numbers you enter — it does not know what dose, vial size or concentration is appropriate for you, and individual circumstances vary. Confirm every value against your product label, a licensed pharmacist, or your prescriber before drawing anything.
Frequently Asked Questions
What's the difference between "Target a dose" and "I know my draw" mode?
"Target a dose" starts from the dose you want and calculates the draw volume and syringe units needed. "I know my draw" works the opposite direction — starting from a syringe reading you already have and calculating what dose that delivers. Both use the same underlying concentration.
Why do I need to know bacteriostatic water amount specifically?
Concentration depends on how much liquid the peptide is dissolved into — the same 10mg vial produces a much stronger solution with 1mL of water than with 5mL. Getting this number right is the single most important step in the whole calculation.
What if my compound is a blend of two or more peptides?
Check "This is a blend" (or enter a recognized blend name) to reveal per-compound mg fields. The calculator then shows a breakdown of how much of each individual compound a given draw delivers, in addition to the total draw volume.
Why does the syringe visual show a warning sometimes?
If your calculated draw volume is larger than the syringe capacity you selected, the tool flags it — you'd need a larger syringe or a more concentrated mix to draw that dose in one go.
Does this calculator tell me what dose I should take?
No. It converts a dose you specify into a draw volume and syringe reading. It does not recommend, validate, or suggest a dose amount — that determination should come from your own research, a licensed clinician, or your product's labeling.
What's the "Example Conversion Table" for?
It shows a range of common dose amounts converted to draw volume and syringe units, purely as mathematical reference points based on your entered vial size and water amount — not a suggested dosing schedule.
Can I use this for hormone products like testosterone, not just peptides?
Yes — the underlying math (concentration, draw volume, syringe units) is identical regardless of compound. For weekly-total TRT protocols specifically, the TRT Dose Calculator is built around that particular framing.
Why is my "doses per vial" number not a whole number rounded up?
It's intentionally rounded down (floored) — a partial dose isn't a usable full dose, so the count reflects how many complete doses the vial can actually deliver.
Is this the same calculator used inside the Peptide Plug app?
Yes — this page uses the same reconstitution math as the in-app Cycle Builder calculator. The app additionally saves your cycles, tracks dose history over time, and sends low-stock and expiration alerts.
Does this tool save or send my numbers anywhere?
No — every calculation happens locally in your browser and nothing is saved, logged, or transmitted. To track your actual dose history over time, see the full Peptide Plug app.
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