Know exactly what to draw, every injection. Plus a free tracker if you want one.
Free · No sign-up needed · Private
Pick your group, then your tool.
Weekly dose to syringe units
TRT dosage calculator TRT microdosing calculator HCG dosage calculator Steroid dosage calculator Ester bioavailability and half-lifeMixing and how much to draw
Peptide dosage calculator Peptide reconstitution (how much water) BPC-157 calculator BPC-157 + TB-500 blendWeight-loss injections
Semaglutide (Ozempic, Wegovy) Tirzepatide (Mounjaro, Zepbound) Retatrutide GLP-1 titration calculatorUnderstand your numbers
Free testosterone calculator Free testosterone index BMI calculatorNew to injections or dialling in a protocol? Our free injection and dosage guides explain the maths, titration, storage, and safety in plain language.
InjectBuddy is a free suite of browser-based dosing tools for injectable hormone therapy and peptide protocols. Work out your exact injection volume and insulin-syringe units for testosterone replacement therapy (TRT), GLP-1 medications such as semaglutide and tirzepatide, HCG, and research peptides like BPC-157 and TB-500 — plus reconstitution maths, BMI, and the free testosterone index.
For calculators, no login is needed and your calculation inputs stay in your browser. Saved dose and blood-panel tracking needs a free account; your records are private to your account. Each tool converts your prescribed dose and vial concentration into a clear draw volume and the matching mark on a U-100 syringe, so the number on the label and the line on the barrel finally line up. InjectBuddy performs arithmetic only and is not medical advice — always confirm your dose and protocol with your prescribing doctor, nurse, or pharmacist. The two most-used tools are the Testosterone (TRT) dosage calculator and the peptide dosage calculator — start there if you inject testosterone or reconstitute peptide vials.