Peptide Calculator

A peptide calculator — also called a peptide dosage calculator, peptide reconstitution calculator, or peptide concentration calculator — is a free online tool that helps researchers and clinicians determine the exact amount of solution to draw into a syringe for each injection. You select your vial size (mg), the volume of bacteriostatic (BAC) water added (mL), your desired dose (mg), and your syringe size. The tool calculates concentration, injection volume in mL, and syringe units automatically — scaled to the syringe you’re actually using.

To calculate peptide dosage without an online peptide calculator, follow this peptide injection math: (1) Find the concentration: mg/mL = vial mg ÷ BAC water mL. (2) Find draw volume: mL = dose (mg) ÷ concentration (mg/mL). (3) Convert to units: units = mL × 100, regardless of syringe size. This is the core peptide dosing guide used across clinical and research settings. Our free peptide calculator automates all three steps instantly and checks the result against your syringe’s capacity.

The amount of bacteriostatic water depends on your vial size, your target dose, and the syringe you plan to use. Common reconstitution volumes in peptide therapy dosage practice are 1 mL, 2 mL, or 3 mL. More BAC water creates a lower concentration, which means larger, easier-to-read syringe draws — but it must still fit within your syringe’s capacity. Use our BAC water calculator to test different water volumes and syringe sizes together to see the resulting units instantly. For a 5 mg vial, adding 2 mL gives a 2.5 mg/mL concentration; a 0.5 mg dose would require drawing 20 units, which fits comfortably on a 30u, 50u, or 100u syringe.

Insulin-style syringes are commonly sized at 30 units (0.3 mL), 50 units (0.5 mL), and 100 units (1.0 mL) — all marked so that 1 mL equals 100 units. Smaller syringes (30u, 50u) have unit lines spaced further apart, making low-volume draws easier to read precisely, but they hold less total liquid. If your calculated draw volume exceeds your syringe’s maximum, the calculator will flag it — you’d need a larger syringe or a more concentrated (less diluted) solution.

mg (milligrams) and mcg (micrograms) both measure mass — 1 mg = 1,000 mcg. This calculator works in mg for all inputs. If your protocol specifies a dose in mcg, simply divide by 1,000 to convert before entering (e.g. 250 mcg = 0.25 mg). When following a peptide dosage chart, always confirm which unit the protocol uses before calculating.

Yes. This online peptide calculator works for any lyophilized peptide including BPC-157, TB-500, CJC-1295, Ipamorelin, GHK-Cu, Semaglutide, Tirzepatide, Retatrutide, MK-677, and others. The peptide reconstitution math is the same regardless of compound — only the reference dose differs. Select your vial amount, BAC water volume, desired dose, and syringe size, and the calculator handles the rest.

After calculating, click the Share Result button. This copies a URL to your clipboard that encodes all your input values — including syringe size — as URL parameters. Anyone who opens the link will see the same calculator pre-filled with your exact inputs — no account or sign-up required.