Calculators

Free peptide-dosing calculators. No signup. Math you can verify.

Every calculation runs in your browser — nothing is sent to a server, nothing is stored. You can read the formulas, copy-paste the math into a spreadsheet, and double-check us. We'd rather you trust the answer because you verified it than because we said so.

These tools illustrate dose math; they are not medical advice. Discuss any clinical decision with your prescribing clinician.

The one calculation everything else is built on

Reconstitution math is a single division, and almost every dosing error traces back to getting it wrong. Concentration = peptide mass ÷ volume of bacteriostatic water. A 5 mg vial reconstituted with 2 mL gives 2.5 mg/mL.

The step that trips people is the syringe. A U-100 insulin syringe is marked in insulin units, not millilitres, and 100 units = 1 mL. So each unit is 0.01 mL. To draw 250 mcg from that 2.5 mg/mL vial you need 0.1 mL, which is 10 units — a tenth of the syringe, not a tenth of the vial.

Two consequences worth internalising. The amount of water you add does not change how much peptide is in the vial; it only changes how many units correspond to a given dose. And units are a volume measure, so a dose expressed in units is meaningless unless the concentration is stated alongside it — which is why “I take 10 units” on a forum tells you nothing.

Every calculator here shows its working for exactly this reason. You can reproduce any result with a pen, and we would rather you did.

Why no accounts? Calculators with logins exist to harvest your data. Ours don't. If you want to save a calculation, screenshot it or paste the inputs into a document. The browser does the math; we don't see it.