Peptide calculator you can verify.
Reconstitute any lyophilized peptide with precision. Enter the vial size, bacteriostatic water and research dose to get exact U-100 syringe units, mL, concentration and draws per vial — then plan supplies and print a vial label. The Royal Trust Standard.
- U-100syringe units
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- Concentration
mcg/mL = vial mg × 1,000 ÷ water mL - Volume
mL = amount mcg ÷ mcg/mL - Units
units = mL × 100 (U-100)
Example: 5 mg + 2 mL = 2,500 mcg/mL. 250 mcg = 0.10 mL = 10 units, 20 draws per vial.
Calculate your syringe draw
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Conversion charts
Your vial, live
5 mg vial · 2 mL water · 2,500 mcg/mL
| Amount | Units | mL | Draws |
|---|
mcg per syringe unit
Tap a cell to load it into the calculator.
| Vial | 1 mL | 2 mL | 2.5 mL | 3 mL |
|---|---|---|---|---|
| 2 mg | 20 | 10 | 8 | 6.7 |
| 5 mg | 50 | 25 | 20 | 16.7 |
| 10 mg | 100 | 50 | 40 | 33.3 |
| 15 mg | 150 | 75 | 60 | 50 |
| 20 mg | 200 | 100 | 80 | 66.7 |
| 30 mg | 300 | 150 | 120 | 100 |
| 40 mg | 400 | 200 | 160 | 133.3 |
How the peptide calculator works
Every result comes from three steps you can check by hand. This is the core of peptide reconstitution math:
- Concentration
mcg/mL = peptide mg × 1,000 ÷ water mL - Volume to draw
mL = desired amount mcg ÷ concentration - Syringe units
units = mL × 100 (U-100 syringe)
| Vial | Water | Concentration | Amount | Units |
|---|---|---|---|---|
| 5 mg | 2 mL | 2,500 mcg/mL | 250 mcg | 10 |
| 10 mg | 2 mL | 5,000 mcg/mL | 1 mg | 20 |
| 10 mg | 1 mL | 10,000 mcg/mL | 500 mcg | 5 |
| 15 mg | 3 mL | 5,000 mcg/mL | 2.5 mg | 50 |
| 30 mg | 3 mL | 10,000 mcg/mL | 2 mg | 20 |
Choosing a water volume
Water doesn't change how much peptide is in the vial, only its concentration. More water gives larger, easier-to-read draws for small amounts; less water gives smaller draws for large amounts, where small measuring errors matter more. A practical range is 5–50 units per draw. The calculator suggests volumes that land on whole units, and Reverse mode finds the exact volume for any mark: water mL = peptide mcg × (units ÷ 100) ÷ amount mcg.
Understanding U-100 syringe units
U-100 insulin syringes are graduated so 100 units = 1 mL, so 1 unit = 0.01 mL on 0.3 mL, 0.5 mL and 1 mL barrels alike. Smaller barrels have finer, more widely spaced markings, which makes a 0.3 mL syringe easier to read for draws under 30 units. International Units (IU) are different: they measure biological activity and can't be converted from mg with a universal formula.
Storage basics
Lyophilized material is typically stored cool, dark and dry. Reconstituted material is commonly kept refrigerated at 2–8 °C, protected from light, and used within about four weeks. Label every vial with the compound, concentration and date — the vial-label button does this — and follow the product's documentation.
Peptide calculator questions
No matching questions. Try “units”, “water” or “blend”.
Divide the peptide amount in mcg by the bacteriostatic water volume in mL to get the concentration in mcg/mL. Divide your desired amount by the concentration to get the volume in mL, then multiply by 100 to convert to units on a U-100 insulin syringe.
5 mg in 2 mL equals 2,500 mcg/mL, or 25 mcg per unit. 250 mcg divided by 25 mcg per unit equals 10 units (0.10 mL) on a U-100 syringe.
10 mg in 2 mL equals 5,000 mcg/mL. 1 mg is 1,000 mcg, so 1,000 divided by 5,000 equals 0.20 mL, which is 20 units on a U-100 syringe.
There is no single correct volume; 1–3 mL is common for 2–10 mg vials. More water makes each unit contain less peptide, which makes small amounts easier to measure accurately. Use the calculator's whole-unit suggestions or Reverse mode to find a volume that gives a convenient draw.
No. The total peptide in the vial stays the same; extra water only lowers the concentration, so you draw a larger volume for the same amount.
1 milligram (mg) equals 1,000 micrograms (mcg). A 5 mg vial contains 5,000 mcg of peptide.
U-100 syringes are marked so that 100 units equal 1 mL. One unit therefore equals 0.01 mL, regardless of whether the syringe holds 0.3, 0.5 or 1 mL in total.
There are 100 units in 1 mL on a U-100 insulin syringe, so 0.5 mL is 50 units and 0.1 mL is 10 units.
It depends on the concentration. Divide the concentration in mcg/mL by 100. For example, a 10 mg vial with 2 mL of water is 5,000 mcg/mL, so each unit contains 50 mcg.
Yes. On any U-100 syringe one unit is 0.01 mL. Smaller syringes simply have finer, more widely spaced markings, which makes small draws easier to read.
Divide the total peptide in the vial by the amount per draw. A 10 mg vial (10,000 mcg) with 500 mcg per draw contains 20 draws, regardless of how much water was added.
Multiply the peptide amount in mcg by the target units divided by 100, then divide by the desired amount in mcg. For a 5 mg vial, 250 mcg at 10 units: 5,000 × 0.10 ÷ 250 = 2 mL. Reverse mode does this automatically.
Every draw contains each peptide in the same ratio as the vial. Multiply each peptide's mcg by the draw volume divided by the total water. In a vial with 5 mg of each of two peptides in 2 mL, a 10-unit (0.10 mL) draw contains 250 mcg of each.
Lyophilized means freeze-dried. Removing water keeps peptides stable during storage and shipping; the powder is reconstituted with a diluent before use.
Bacteriostatic water is sterile water containing 0.9% benzyl alcohol, a preservative that allows multiple withdrawals from the same vial. Plain sterile water has no preservative and is intended for single use.
Reconstituted peptides are commonly stored refrigerated at 2–8 °C, protected from light, and used within about four weeks. Always follow the storage guidance for the specific product and its certificate of analysis.
No. IU measure biological activity and are specific to each compound, so they cannot be converted from mg with a universal formula. Syringe units are a volume marking: 1 unit equals 0.01 mL.
The calculator is free and needs no account. Calculations run in your browser; saved calculations are kept only on your device and are never sent to a server.
No. It is a mathematical tool for laboratory concentration and measurement only. Royal Peptides does not provide dosing advice or use instructions, and products are sold strictly for research, not for human or veterinary use.
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Research use only. This calculator is a mathematical tool for laboratory reconstitution and measurement and does not provide dosing advice. Always verify calculations independently. Updated .