How to Use a Peptide Calculator

The three numbers you need

Step by step

1. Open the peptide calculator and keep the Reconstitution tab.
2. Enter the vial amount and pick its unit.
3. Enter the liquid added in mL.
4. Enter your amount and pick its unit. The calculator converts mg and mcg exactly.
5. Pick the syringe you have. Results round to its markings, and you’ll be warned if a volume is too small to measure or too big for one fill.
6. Read the result: the big number is the U-100 units (or mL), with the concentration, nearest marking and portions per vial underneath.

Reading the result

• Volume / units: the exact volume for your amount. On a U-100 syringe, 1 unit is 0.01 mL.
• Nearest marking: the closest line you can actually read, and how much it really holds. If it is more than 5% away from the exact volume, you’ll see a warning.
• Concentration: amount per mL, in mg/mL and mcg/mL.
• Portions per vial: how many times your amount fits in the vial (arithmetic only).

Check the answer by hand

Two divisions confirm any result. Say the vial is 5 mg, you added 2 mL, and your amount is 250 mcg:

1. 5 mg ÷ 2 mL = 2.5 mg/mL = 2,500 mcg/mL.
2. 250 mcg ÷ 2,500 mcg/mL = 0.1 mL.
3. 0.1 mL × 100 = 10 units.

If your answer is off by exactly 1,000 times, one number is in mg and another in mcg.

Common mistakes

• Typing mcg into an mg field (or the reverse).
• Treating syringe “units” as IU. They are a volume mark: 100 per mL on a U-100 syringe.
• Using a 1 mL syringe for a very small volume. The 0.3 mL and 0.5 mL syringes have finer markings.
• Rounding the concentration first and then multiplying. The calculator keeps full precision until the end.

Frequently asked questions