About This Calculator

Our Purpose

This site was created to make dosage volume calculations more accessible and understandable for patients who self-administer injectable medications as part of a medically prescribed treatment plan. Testosterone replacement therapy patients are among the most common users of this calculator — many TRT protocols involve home self-injection, and accurately converting a milligram dose to a milliliter draw volume is a skill that every self-injecting patient needs to master.

The calculator applies the standard pharmacological formula — dividing desired dose (mg) by vial concentration (mg/mL) — to produce an accurate draw volume. This is the same formula used in clinical and hospital settings worldwide. Providing it in an instant, accessible calculator removes the arithmetic burden and reduces the risk of human calculation error.

How the Calculation Works

The fundamental formula is: Volume (mL) = Dose (mg) ÷ Concentration (mg/mL). This formula works because milligrams in the numerator and the denominator cancel out, leaving a pure volume in milliliters. For example, a 150mg dose from a 250mg/mL testosterone vial: 150 ÷ 250 = 0.60mL.

The formula is universal — it applies to testosterone enanthate, testosterone cypionate, testosterone propionate, vitamin B12 injections, hormone therapy preparations, peptides, and any other injectable medication where the concentration is expressed in mg/mL.

Who This Calculator Is Designed For

This calculator is primarily designed for:

• TRT patients self-administering prescribed testosterone injections at home and needing to convert their milligram dose to the correct milliliter draw volume
• Patients on injectable hormone therapies including testosterone preparations at various concentrations (100mg/mL through 400mg/mL)
• Patients receiving injectable vitamin or supplement therapies who need to calculate draw volumes
• Healthcare students and carers learning the principles of injectable medication dosage calculation
• Anyone who needs to convert mg to mL for any injectable or liquid medication preparation

This calculator is not intended to replace medical advice or clinical dosage verification. Always confirm your calculated dose with your prescribing healthcare professional.

TRT and Medication Dosage Conversion Use Cases

The most common use case for this calculator is testosterone replacement therapy (TRT). TRT patients are prescribed a weekly milligram dose by their physician — commonly 100mg to 200mg per week — and must convert this to a draw volume based on their vial concentration. Common testosterone concentrations include 200mg/mL (testosterone cypionate, standard in the US) and 250mg/mL (testosterone enanthate, common in Europe and Australia).

Other injectable medication users include patients receiving vitamin B12 injections, iron dextran, hormone replacement therapy (including HRT for trans individuals), peptide therapies, and other injectable preparations. The formula is identical regardless of the specific medication — only the concentration and dose values change.

What We Offer

• An instant MG to ML dosage calculator with quick-select concentration presets
• Comprehensive TRT guides covering testosterone enanthate, testosterone cypionate, injection frequencies, and concentrations
• Concentration-specific reference guides for 100mg/mL through 400mg/mL
• Syringe selection and measurement guides for accurate administration
• A comprehensive TRT FAQ covering common questions about dosing, frequency, and administration

Educational Use Only

All content on this website — including the calculator, TRT guides, dosage tables, and reference materials — is strictly for informational and educational purposes only. This site does not provide medical advice, diagnosis, or treatment recommendations. Testosterone is a prescription medication. Always consult a qualified healthcare professional before making any changes to your medication or treatment plan.