Last Updated: May 2026

Accurate peptide calculator results in seconds. Enter your vial size, bacteriostatic water volume, and target dose — our tool instantly converts your peptide dosage into precise syringe units. No math errors. No guesswork. Research-grade precision for every calculation.

Used by researchers worldwide for peptide reconstitution, BAC water mixing, and syringe unit conversion. Whether you are working with a 2mg, 5mg, or 10mg vial, this tool delivers the exact draw volume you need.

Using this peptide reconstitution calculator takes under 30 seconds. Follow these three steps:

Step 1 — Enter Vial Size (mg): Input the total peptide amount printed on your vial. Common sizes include 2mg, 5mg, 10mg, and 30mg.

Step 2 — Enter BAC Water Volume (mL): Enter how much bacteriostatic water you plan to add. A standard reconstitution uses 1–2mL. This determines your final concentration in mg/mL.

Step 3 — Enter Desired Dose (mcg): Input your target research dose in micrograms. The calculator automatically outputs the exact number of units to draw on a U-100 insulin syringe.

Results update instantly. No refresh needed. Bookmark this page for fast access during every reconstitution session.

The volume of bacteriostatic water you add directly sets your concentration, which in turn controls your dose accuracy. Research best practice recommends these standard ratios as starting points:

2mg vial + 1mL BAC water → 2mg/mL (2,000mcg/mL). Each 10 units = 200mcg.
5mg vial + 2mL BAC water → 2.5mg/mL (2,500mcg/mL). Each 10 units = 250mcg.
10mg vial + 2mL BAC water → 5mg/mL (5,000mcg/mL). Each 10 units = 500mcg.

Always inject the bacteriostatic water slowly down the inside wall of the vial, not directly onto the peptide cake. This technique minimizes mechanical agitation. If the vial has a vacuum, the water will be drawn in automatically. If resistance is felt, gently relieve the vacuum with an empty syringe before adding BAC water. Use our BAC water mixing calculator above to generate custom ratios for any vial size.

Every peptide dosage calculation follows the same fundamental formula. Understanding it means you can verify any calculator result manually:

Draw Volume (mL) = Desired Dose (mcg) ÷ Concentration (mcg/mL)

Example: You have a 10mg vial reconstituted with 2mL BAC water. Concentration = 10,000mcg ÷ 2mL = 5,000mcg/mL. Your desired dose is 500mcg. Draw volume = 500 ÷ 5,000 = 0.1mL. On a U-100 insulin syringe, 0.1mL = 10 units. This is your draw mark.

The most common mistake researchers make is confusing milligrams (mg) with micrograms (mcg). Remember: 1mg = 1,000mcg. The peptide calculator above handles this conversion automatically, but it is worth understanding the relationship when reviewing your results.

Most researchers use a U-100 insulin syringe for peptide administration. On a U-100 syringe, each small tick mark represents 1 unit, which equals 0.01mL. A 10-unit draw = 0.1mL. A 20-unit draw = 0.2mL. The full barrel of a 1mL syringe = 100 units.

Do not confuse U-100 syringes with U-40 syringes. A U-40 syringe has a different scale: 1 unit = 0.025mL. Using a U-40 syringe with U-100 calculations will result in a 2.5x dosing error. Always confirm your syringe type before drawing. Our syringe unit calculator is calibrated for U-100 syringes, which are the standard for peptide research.

For very small doses (under 50mcg), consider adding more BAC water to your vial to create a lower concentration. This spreads your dose across more syringe units, dramatically reducing measurement error.

1. Shaking the vial: As noted above, shaking degrades peptide integrity. Always roll gently.

2. Confusing mg and mcg: This is the single most common dosing error. The calculator prevents it automatically.

3. Using the wrong water: Sterile water has no preservative and should only be used for single-dose vials. Bacteriostatic water is required for multi-dose vials.

4. Incorrect syringe type (U-40 vs U-100): Check your syringe before every draw. The barrel markings differ significantly.

5. Over-pressuring the vial: Injecting more water volume than the vial can hold creates excess pressure and risks contamination. Always add water slowly with a vented needle technique if needed.

Mental math and generic calculators introduce risk. A purpose-built peptide calculator eliminates three critical failure points: unit conversion errors, concentration miscalculation, and syringe misread. For research requiring repeatable, precise dosing protocols, this level of accuracy is non-negotiable.

This tool also removes friction from the calculation process entirely. Instead of reaching for a notepad mid-experiment, researchers input three numbers and receive an immediate, unambiguous result. The result is displayed as a syringe unit count — the most practical unit for bench-side use. No additional conversion is needed.