FREE PEPTIDE CALCULATOR
Peptide calculator
See where to draw.
Enter your vial, the water you added and your dose. See the units on a U-100 insulin syringe, instantly.
A math tool, not medical advice. It calculates from the values you enter and does not choose a dose.
HOW IT WORKS
Three numbers.
One mark on the syringe.
Vial amount
How much peptide the vial holds, printed on the label in mg.
Water added
How much bacteriostatic water you mixed in, in mL. Together with the vial amount this sets the concentration.
Your dose
The amount from your instructions, in mcg or mg. The calculator turns it into syringe units.
Concentration = vial amount ÷ water
Units = dose ÷ concentration × 100
Example: 10 mg in 2 mL is 5 mg/mL, so each unit holds 50 mcg. Reading the syringe: 10 units (0.1 mL) holds 500 mcg, and a full 100-unit syringe (1 mL) holds 5 mg. How rounding works →
RECONSTITUTION CHART
How much is in
each unit?
Concentration for common vial sizes and water volumes, and how much peptide each unit on a U-100 syringe holds.
| Vial | 1 mL water | 2 mL water | 3 mL water |
|---|---|---|---|
| 5 mg | 50 mcg5 mg/mL | 25 mcg2.5 mg/mL | 16.67 mcg1.667 mg/mL |
| 10 mg | 100 mcg10 mg/mL | 50 mcg5 mg/mL | 33.33 mcg3.333 mg/mL |
| 15 mg | 150 mcg15 mg/mL | 75 mcg7.5 mg/mL | 50 mcg5 mg/mL |
| 20 mg | 200 mcg20 mg/mL | 100 mcg10 mg/mL | 66.67 mcg6.667 mg/mL |
Bold: mcg in each unit. Below it: concentration. 1 unit = 0.01 mL on a U-100 syringe. Values are arithmetic, not recommendations.
Printable chart and formulas → · Convert mg to syringe units →
CALCULATORS BY PEPTIDE
Same math,
your vial sizes.
FOR THE NEXT TIME
This page forgets.
Dosii remembers.
Use this page for a quick check. If you calculate the same vial every week, the Dosii iPhone app keeps it ready.
No account. No subscription. Your numbers stay on your iPhone.
This page
- One calculation at a time
- 100-unit syringe
- Clears when you leave
Dosii app
- Saved calculations, named and ready
- Water suggestions for clean marks
- 30, 50 and 100-unit syringes
- Cost per dose
- Works offline, stays on your iPhone
QUESTIONS
Good to know.
How many units should I draw?
This calculator converts the numbers you enter into syringe units: your dose divided by the concentration, times 100 on a U-100 syringe. It checks the arithmetic, not the dose. Use the amount from your own instructions.
What is a unit on an insulin syringe?
On a U-100 syringe, 100 units equal 1 mL, so one unit is 0.01 mL. 30-, 50- and 100-unit syringes all use this same scale. They differ in how much they hold, not in what a unit means.
How does the amount of water change the result?
Water changes the concentration, not the amount of peptide in the vial. Adding more water spreads the same peptide through more liquid, so the same dose takes more units. The reconstitution chart on this page shows how common water volumes change the amount in each unit.
Why do peptide calculators sometimes disagree?
Usually because of units (mg versus mcg) or rounding. This calculator keeps full precision internally and rounds only the displayed result to the nearest half unit. Open “Show the math” to check each step.
Does this calculator save my numbers?
No. The values you enter stay in this browser tab and disappear when you leave or reload; they are never stored or sent. Separately, the website counts visits, App Store clicks and that the calculator was used, without the numbers you enter. If you want to keep a calculation and reuse it, the Dosii iPhone app saves it on your device. Privacy details.
Dosii explains terminology and calculates from the values you enter. It does not choose a dose or verify a product. Follow product-specific instructions and guidance from a qualified healthcare professional.