Peptide calculator

A free, open-source peptide reconstitution calculator. Enter the vial size (mg), the water added (mL) and the amount wanted (mcg or mg). It returns the concentration and the units to draw on a U-100 insulin syringe.

Live page: https://prismresearchlabs.github.io/peptide-calculator/

Chrome extension: Peptide Calculator on the Chrome Web Store

The math

• Concentration: mg/mL = vial mg ÷ water mL
• One unit on a U-100 syringe is 0.01 mL, so each unit holds mg/mL × 10 mcg.
• Units for an amount: units = (amount mg ÷ mg/mL) × 100

Example: 10 mg in 2 mL is 5 mg/mL. Each unit holds 50 mcg, so 250 mcg is 5 units.

Reconstitution chart

Vial	1 mL water	2 mL water	3 mL water
5 mg	5 mg/mL · 50 mcg/unit	2.5 mg/mL · 25 mcg/unit	1.67 mg/mL · 16.7 mcg/unit
10 mg	10 mg/mL · 100 mcg/unit	5 mg/mL · 50 mcg/unit	3.33 mg/mL · 33.3 mcg/unit
20 mg	20 mg/mL · 200 mcg/unit	10 mg/mL · 100 mcg/unit	6.67 mg/mL · 66.7 mcg/unit
30 mg	30 mg/mL · 300 mcg/unit	15 mg/mL · 150 mcg/unit	10 mg/mL · 100 mcg/unit
50 mg	50 mg/mL · 500 mcg/unit	25 mg/mL · 250 mcg/unit	16.7 mg/mL · 166.7 mcg/unit
100 mg	100 mg/mL · 1,000 mcg/unit	50 mg/mL · 500 mcg/unit	33.3 mg/mL · 333.3 mcg/unit

Guides

• Peptide calculator with a dose chart
• How to reconstitute peptides: 7 steps
• How to read a peptide certificate of analysis
• Prism Labs lab report index: lot numbers, test dates and purity for every lot

Notes

Math only. It does not choose an amount for you and is not medical advice. For laboratory research use only.

Maintained by Prism Labs, a US supplier of research peptides with a third-party lab report for every lot. MIT licensed.