Peptide Calculator
Reconstitution, concentration and U-100 syringe units for laboratory research. Free, no sign-up.
Draw -- units
How to use the peptide calculator
- Pick the peptide from the list, or type the amount in the vial in milligrams (mg). The size is printed on the vial label.
- Enter the bacteriostatic water you will add, in millilitres (mL).
- Enter the amount you want to measure out, in mg or micrograms (mcg).
- Read the result: the concentration of the solution, the volume in mL, and the matching mark on a U-100 syringe. Tap Copy link to this calculation to save it or share it with your lab.
The math behind it
The calculator does three steps. You can check any result by hand:
Concentration (mcg/mL) = vial mg × 1,000 ÷ water mL
Volume (mL) = amount (mcg) ÷ concentration (mcg/mL)
U-100 units = volume (mL) × 100
Worked example
A 10 mg vial with 2 mL of bacteriostatic water holds 10,000 mcg in 2 mL, so the concentration is 5,000 mcg/mL (5 mg/mL). To measure out 250 mcg: 250 ÷ 5,000 = 0.05 mL, which is the 5-unit mark on a U-100 syringe.
Quick reference table
Concentration for common vial sizes and water volumes. On a U-100 syringe, 1 unit is 0.01 mL, so the last column is how much peptide each unit mark holds.
| Vial | Water | Concentration | Per unit (0.01 mL) |
|---|---|---|---|
| 5 mg | 1 mL | 5 mg/mL | 50 mcg |
| 5 mg | 2 mL | 2.5 mg/mL | 25 mcg |
| 5 mg | 3 mL | 1.67 mg/mL | 16.7 mcg |
| 10 mg | 1 mL | 10 mg/mL | 100 mcg |
| 10 mg | 2 mL | 5 mg/mL | 50 mcg |
| 10 mg | 3 mL | 3.33 mg/mL | 33.3 mcg |
| 20 mg | 2 mL | 10 mg/mL | 100 mcg |
| 20 mg | 3 mL | 6.67 mg/mL | 66.7 mcg |
| 20 mg | 4 mL | 5 mg/mL | 50 mcg |
Rounded to 3 significant figures. Use the calculator above for exact values.
Choosing how much water to add
More water makes a weaker solution, so each unit mark holds less peptide. That makes small amounts easier to measure accurately. Less water makes a stronger solution, so the same amount fits in fewer units.
- If the result is under 5 units, small reading errors matter a lot. Add more water so the amount lands higher on the scale.
- If the result is over 50 units, the measurement uses most of a 0.5 mL syringe. Use less water, or a 1 mL syringe.
- Write the date and the concentration on the vial once it is mixed, so everyone in the lab reads it the same way.
Mixing and storage basics
- Let the vial reach room temperature, then add the water slowly down the inside wall of the vial.
- Swirl gently until clear. Do not shake: shaking can damage peptide chains.
- Before mixing, store vials sealed at 2–8 °C, or at −20 °C for long-term storage. After mixing, keep the vial refrigerated at 2–8 °C.
More detail: reconstitution guide (water ratios and storage), how long reconstituted peptides last, bacteriostatic vs sterile water and choosing syringes.
What you need
- Bacteriostatic water3 mL and 10 mL vials
- U-100 syringesMarked in units, 100 units = 1 mL
- All research peptidesEvery size, with live prices and stock
- Lab resultsCertificates of analysis by batch
Frequently asked questions
What is a peptide calculator?
A peptide calculator turns three numbers (the peptide in the vial in mg, the bacteriostatic water added in mL, and the amount you want to measure) into the solution's concentration, the volume to draw in mL and the matching mark on a U-100 syringe.
How many units is 0.1 mL on a U-100 syringe?
10 units. A U-100 syringe has 100 unit marks per millilitre, so 1 unit is 0.01 mL.
How much bacteriostatic water should I add to a 10 mg vial?
Labs commonly use 1 to 3 mL. With 2 mL the solution is 5 mg/mL, so each unit mark holds 50 mcg. Choose the volume that keeps your measurements between about 5 and 50 units.
How do I convert mg to mcg?
Multiply by 1,000: 1 mg is 1,000 mcg, so 0.25 mg is 250 mcg. The calculator accepts either unit.
Does the water volume change how much peptide is in the vial?
No. The total peptide in the vial stays the same. More water lowers the concentration, so the same amount takes up more volume and more unit marks.
Does the calculator work for blends like KLOW or Wolverine?
Yes. Enter the total mg printed on the vial label. The concentration shown is for the whole blend; each component's share follows the ratio on the label.
Is the peptide calculator free?
Yes. No sign-up is needed, and the Copy link button saves your numbers so you can reopen the same calculation.
Are these products for human use?
No. All Prime Peptide Solutions products are sold for laboratory research use only and are not for human or veterinary use.
Disclaimer: This calculator is provided strictly for educational and informational purposes only. Prime Peptide Solutions assumes no liability for any calculations, errors, misuse, or outcomes resulting from the use of this tool. All products are intended for research and laboratory use only and are not for human consumption.