Testosterone Dosage Calculator

Calculate injection volume, insulin-syringe units, active testosterone, and ester half-life estimates from weekly dose, concentration, and injection frequency.

IMPORTANT MEDICAL DISCLAIMER

This calculator is an educational math tool. It is NOT medical advice, not a diagnosis, and not a prescription. Anabolic-androgenic steroids are controlled substances in many jurisdictions.

Testosterone therapy requires appropriate diagnosis, ongoing monitoring including hematocrit, PSA, lipids, and estradiol where clinically indicated, and supervision by a licensed prescriber. Misuse can increase cardiovascular, infertility, endocrine-suppression, and dependence risks.

Testosterone Ester Dosage Calculator

Convert a prescribed weekly testosterone ester dose into the amount per injection, the injection volume, and the approximate U-100 insulin syringe units to draw.

The calculator estimates active testosterone content from ester chemistry and steady state from the commonly cited half-life for the selected preparation.

Testosterone esters differ mainly in release rate and how much of the ester mass is testosterone by weight. This tool does not validate whether testosterone is appropriate for any person.

Ester

Vial concentration

Weekly dose

Injection frequency

Syringe size

How the Math Works

Core formulas used to convert weekly ester dose into injection volume and pharmacokinetic estimates.

All dose inputs are ester mass. Active testosterone estimates apply the ester-specific testosterone fraction by molecular weight.

1. Injection dose:

mg per injection = weekly mg × interval days ÷ 7

2. Injection volume:

volume ml = (weekly × interval ÷ 7) ÷ concentration

3. U-100 syringe units:

units = volume × 100

4. Ester estimates:

active T = weekly × ester%

steady state ≈ 5 × half-life

Clinical Guidance

Use these estimates only as context for licensed medical care.

Replacement Range

The Endocrine Society guideline frames testosterone therapy as treatment for clinically diagnosed hypogonadism, with typical replacement dosing commonly falling around 75-200 mg/week depending on formulation and clinical response.

Monitoring & Ester Choice

Clinical decisions depend on symptoms, testosterone labs, hematocrit, prostate risk, fertility goals, adverse effects, and dosing interval. Longer esters reach stable levels over several half-lives; loading and monitoring plans should come from the prescriber.

Ester Comparison Table

Testosterone content by ester mass, commonly cited half-lives, and typical vial concentrations.

EsterTestosterone content (%)Half-life (days)Typical conc. (mg/ml)NotesSources
Testosterone (base / suspension)1000.550, 100Unesterified testosterone; short duration and rapid peak after injection.[5], [8]
Testosterone Propionate83.70.8100Short-acting ester usually requiring frequent injections.[5], [8]
Testosterone Phenylpropionate73.51.5100Intermediate-short ester used in some multi-ester blends.[5], [7]
Testosterone Enanthate724.5200, 250Long-acting ester; common TRT choice dosed weekly or twice weekly.[3], [4], [6]
Testosterone Cypionate69.98100, 200, 250Long-acting; FDA-approved (Depo-Testosterone) for male hypogonadism.[1], [4], [6]
Testosterone Decanoate63.215100Long ester commonly used as part of multi-ester testosterone blends.[5], [7]
Testosterone Undecanoate (IM, castor oil)61.321250Very long-acting IM depot (Aveed/Nebido); clinic-administered every ~10 weeks after loading.[2], [4]
Sustanon 250 (blend)70.98250Four-ester blend (propionate/phenylpropionate/isocaproate/decanoate) = 176 mg testosterone per 250 mg.[4], [7]

Published Sources & Academic Literature