How a Reverse Peptide Calculator Works
Convert a known prepared concentration and U-100 syringe-unit mark into liquid volume and dose mass in mcg and mg.
7 min read · Educational information only
Calculation flow
Concentration
known mg/mLU-100
drawn unitsVolume
units ÷ 100Dose mass
mg and mcgWhat Reverse mode solves
Standard mode starts with vial amount, liquid volume, and target dose to calculate syringe units. Reverse mode is for a solution that is already prepared: enter its known concentration and the U-100 units drawn to calculate the corresponding volume and dose mass.
The reverse formula
First convert U-100 units to milliliters by dividing by 100. Multiply that volume by the known concentration in mg/mL to obtain dose mass in milligrams, then multiply by 1,000 to express the same mass in micrograms.
- Drawn volume = U-100 units ÷ 100.
- Dose mg = concentration mg/mL × drawn volume mL.
- Dose mcg = dose mg × 1,000.
It is not an optimization recommendation
The quick selections for 5, 10, 15, and 20 units are input shortcuts only. The website does not identify a best syringe mark, concentration, or dose.
Check syringe capacity
Select the capacity printed on the U-100 syringe. The calculator warns when the units entered exceed that capacity, but it cannot verify the markings on the physical device.
Check the math in the calculator
Enter your own values and inspect the formula, units, syringe preview, and warnings together.
Open the peptide calculator