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TRT dosage calculator
Turn your weekly testosterone dose into the exact mL and insulin-syringe units to draw per injection – and see how long a vial will last. Full weekly dosage chart below.
The formula: mL per injection = (your prescribed weekly dose in mg ÷ injections per week) ÷ vial concentration in mg/mL. On a U-100 insulin syringe, multiply the mL by 100 for units. For example, a prescribed 150 mg a week, injected twice weekly from a 200 mg/mL vial, is 75 mg per shot: 0.375 mL, or 37.5 units. The arithmetic is the same for testosterone cypionate and enanthate; only the concentration printed on the vial changes it.
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This page splits one compound at one weekly total. The two things it deliberately does not do are plan several compounds on one timeline and show you how flat a more frequent schedule actually makes the curve.
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Weekly TRT dosage by protocol
Five weekly totals from 100 to 200 mg, split across the four schedules people actually use, with the insulin-syringe units for each of the three standard vial concentrations. All unit figures assume a U-100 syringe (100 units = 1 mL). "Every other day" is calculated as 3.5 injections per week.
| Weekly dose | Schedule | mg per injection | Units @ 100 mg/mL | Units @ 200 mg/mL | Units @ 250 mg/mL |
|---|---|---|---|---|---|
| 100 mg per week | |||||
| 100 mg | Once weekly | 100 mg | 100 u | 50 u | 40 u |
| 100 mg | Twice weekly | 50 mg | 50 u | 25 u | 20 u |
| 100 mg | Every other day | 28.6 mg | 28.6 u | 14.3 u | 11.4 u |
| 100 mg | Daily | 14.3 mg | 14.3 u | 7.1 u | 5.7 u |
| 125 mg per week | |||||
| 125 mg | Once weekly | 125 mg | 125 u | 62.5 u | 50 u |
| 125 mg | Twice weekly | 62.5 mg | 62.5 u | 31.2 u | 25 u |
| 125 mg | Every other day | 35.7 mg | 35.7 u | 17.9 u | 14.3 u |
| 125 mg | Daily | 17.9 mg | 17.9 u | 8.9 u | 7.1 u |
| 150 mg per week | |||||
| 150 mg | Once weekly | 150 mg | 150 u | 75 u | 60 u |
| 150 mg | Twice weekly | 75 mg | 75 u | 37.5 u | 30 u |
| 150 mg | Every other day | 42.9 mg | 42.9 u | 21.4 u | 17.1 u |
| 150 mg | Daily | 21.4 mg | 21.4 u | 10.7 u | 8.6 u |
| 175 mg per week | |||||
| 175 mg | Once weekly | 175 mg | 175 u | 87.5 u | 70 u |
| 175 mg | Twice weekly | 87.5 mg | 87.5 u | 43.8 u | 35 u |
| 175 mg | Every other day | 50 mg | 50 u | 25 u | 20 u |
| 175 mg | Daily | 25 mg | 25 u | 12.5 u | 10 u |
| 200 mg per week | |||||
| 200 mg | Once weekly | 200 mg | 200 u | 100 u | 80 u |
| 200 mg | Twice weekly | 100 mg | 100 u | 50 u | 40 u |
| 200 mg | Every other day | 57.1 mg | 57.1 u | 28.6 u | 22.9 u |
| 200 mg | Daily | 28.6 mg | 28.6 u | 14.3 u | 11.4 u |
Your weekly total is set by your prescriber. This chart only does the arithmetic of splitting it: the same weekly dose taken more often means smaller, harder-to-measure injections but a flatter blood level. Check the concentration printed on your own vial before using any row here – 200 mg/mL is the most common, but 100 and 250 mg/mL are both sold.
Testosterone mg to mL chart
The volume and U-100 syringe units for a single injection, at the three common vial strengths. Volumes above 1 mL (100 units) do not fit in one insulin syringe.
| Dose per injection | @ 100 mg/mL | @ 200 mg/mL | @ 250 mg/mL |
|---|---|---|---|
| 10 mg | 0.1 mL · 10 u | 0.05 mL · 5 u | 0.04 mL · 4 u |
| 20 mg | 0.2 mL · 20 u | 0.1 mL · 10 u | 0.08 mL · 8 u |
| 25 mg | 0.25 mL · 25 u | 0.125 mL · 12.5 u | 0.1 mL · 10 u |
| 30 mg | 0.3 mL · 30 u | 0.15 mL · 15 u | 0.12 mL · 12 u |
| 40 mg | 0.4 mL · 40 u | 0.2 mL · 20 u | 0.16 mL · 16 u |
| 50 mg | 0.5 mL · 50 u | 0.25 mL · 25 u | 0.2 mL · 20 u |
| 60 mg | 0.6 mL · 60 u | 0.3 mL · 30 u | 0.24 mL · 24 u |
| 70 mg | 0.7 mL · 70 u | 0.35 mL · 35 u | 0.28 mL · 28 u |
| 75 mg | 0.75 mL · 75 u | 0.375 mL · 37.5 u | 0.3 mL · 30 u |
| 80 mg | 0.8 mL · 80 u | 0.4 mL · 40 u | 0.32 mL · 32 u |
| 100 mg | 1 mL · 100 u | 0.5 mL · 50 u | 0.4 mL · 40 u |
| 125 mg | 1.25 mL · 125 u | 0.625 mL · 62.5 u | 0.5 mL · 50 u |
| 150 mg | 1.5 mL · 150 u | 0.75 mL · 75 u | 0.6 mL · 60 u |
| 200 mg | 2 mL · 200 u | 1 mL · 100 u | 0.8 mL · 80 u |
Units to mg chart
Working backwards from the mark on the syringe: how many milligrams a given number of U-100 units holds at each vial strength. For an amount not listed, switch the calculator to "Units drawn".
| Units drawn | Volume | @ 100 mg/mL | @ 200 mg/mL | @ 250 mg/mL |
|---|---|---|---|---|
| 5 u | 0.05 mL | 5 mg | 10 mg | 12.5 mg |
| 10 u | 0.1 mL | 10 mg | 20 mg | 25 mg |
| 15 u | 0.15 mL | 15 mg | 30 mg | 37.5 mg |
| 20 u | 0.2 mL | 20 mg | 40 mg | 50 mg |
| 25 u | 0.25 mL | 25 mg | 50 mg | 62.5 mg |
| 30 u | 0.3 mL | 30 mg | 60 mg | 75 mg |
| 35 u | 0.35 mL | 35 mg | 70 mg | 87.5 mg |
| 40 u | 0.4 mL | 40 mg | 80 mg | 100 mg |
| 50 u | 0.5 mL | 50 mg | 100 mg | 125 mg |
| 60 u | 0.6 mL | 60 mg | 120 mg | 150 mg |
| 75 u | 0.75 mL | 75 mg | 150 mg | 187.5 mg |
| 100 u | 1 mL | 100 mg | 200 mg | 250 mg |
Daily injection chart
Daily injections (often called microdosing) divide the weekly total by seven. These weekly totals divide evenly, so the daily amount is a whole milligram. At 250 mg/mL several rows fall under 6 units, where half a unit of misdraw is roughly a 10% error.
| Weekly total | mg per day | Units @ 100 mg/mL | Units @ 200 mg/mL | Units @ 250 mg/mL |
|---|---|---|---|---|
| 70 mg | 10 mg | 10 u | 5 u | 4 u |
| 84 mg | 12 mg | 12 u | 6 u | 4.8 u |
| 98 mg | 14 mg | 14 u | 7 u | 5.6 u |
| 105 mg | 15 mg | 15 u | 7.5 u | 6 u |
| 112 mg | 16 mg | 16 u | 8 u | 6.4 u |
| 126 mg | 18 mg | 18 u | 9 u | 7.2 u |
| 140 mg | 20 mg | 20 u | 10 u | 8 u |
| 154 mg | 22 mg | 22 u | 11 u | 8.8 u |
| 168 mg | 24 mg | 24 u | 12 u | 9.6 u |
| 175 mg | 25 mg | 25 u | 12.5 u | 10 u |
The microdosing calculator shows how much flatter a daily schedule makes the curve compared with once or twice a week.
How to read an insulin syringe
Check it says U-100. Every unit figure on this page is for a U-100 syringe, where 100 units fill 1 mL and 1 unit is 0.01 mL. U-40 syringes, sold for some veterinary insulins, put 40 units in 1 mL. Drawing the same number of units on one of those gives two and a half times the volume.
Know the barrel size. U-100 syringes come in 1 mL (100 units), 0.5 mL (50 units) and 0.3 mL (30 units). The smaller barrels spread the same units over a longer scale, which makes small volumes easier to read. Some 0.3 mL syringes are marked in half units.
Count the lines before you draw. The gap between marks is not the same on every size. Count how many lines sit between two numbered marks on your own syringe to know what one line is worth.
Clear air bubbles first. A bubble takes up space in the barrel, so the syringe reads full while it holds less oil. Testosterone is thick, so bubbles rise slowly. If you are unsure how to read your syringe, ask the pharmacist who dispenses it to show you.
Choosing an injection frequency
The ester decides, not the dose. Frequency follows half-life. Testosterone cypionate (t½ ~3.8 days, why not the 8 days on the label) and enanthate (~4.5 days) hold up on weekly or twice-weekly injections. Propionate (~1 day) needs every other day or it swings hard between peak and trough. You can check any ester on the half-life calculator.
More frequent means flatter, not stronger. Splitting 150 mg into two 75 mg shots does not change your weekly exposure. It narrows the gap between peak and trough, which is what people are usually chasing when they report feeling good for three days and flat for four. The microdosing calculator puts a number on how much flatter each schedule gets.
There is a floor on measurable volume. Look at the daily rows above: 100 mg per week on daily injections at 250 mg/mL is 5.7 units. Half a unit of misdraw there is a 9% dosing error. Daily dosing at a low concentration is where that bites hardest. Changing concentration is a prescription change rather than a syringe change.
Wait for steady state before drawing labs. Any change to dose or frequency takes about four to five half-lives to plateau, so roughly two to three weeks on cypionate. Bloodwork drawn before then measures a level that is still climbing. The TRT timeline covers what else is still catching up at that point.
Testosterone cypionate vs enanthate
The two esters behind almost every US TRT injection. On a schedule they behave almost the same. The calculator needs only the concentration printed on your vial.
| Cypionate | Enanthate | |
|---|---|---|
| US products | Depo-Testosterone (Pfizer) and generics | Generic vials; Xyosted autoinjector |
| Vial strengths | 100 and 200 mg/mL | 200 mg/mL (Xyosted: 50, 75 or 100 mg per 0.5 mL) |
| Oil | Cottonseed (Depo-Testosterone) | Sesame (generic vials) |
| Half-life | About 4 days in the one population PK model; the label says 8 | About 4.5 days |
| Testosterone by weight | About 70% | About 72% |
| Label regimen | 50–400 mg every 2–4 weeks | 50–400 mg every 2–4 weeks (Xyosted: weekly under the skin) |
Same schedule, same arithmetic. Their half-lives are close (about 4 and 4.5 days, measured in different ways), so the same weekly total and the same frequency work for either ester. The cypionate half-life page explains why the 8 days on the label and the 4 days in the model are both real numbers.
What actually differs. The oil matters to anyone who reacts to cottonseed or sesame. A milligram of enanthate also carries slightly more testosterone, so moving between the two at the same milligram dose changes the testosterone delivered by about 3%. Switching ester is a prescription change, made with whoever prescribes it.
How your prescriber sets and monitors the dose
The starting dose comes from a range. The Endocrine Society guideline lists 75–100 mg a week of cypionate or enanthate, or 150–200 mg every two weeks. It aims for a testosterone level in the middle of the normal range. The dose is then adjusted to lab results and symptoms.
Labs are drawn midway between injections. For cypionate or enanthate the guideline measures testosterone at the midpoint of the dosing interval. A mid-interval level above 600 ng/dL (about 21 nmol/L) or below 350 ng/dL (about 12 nmol/L) is its signal to change the dose or the frequency. Follow-up comes 3–12 months after starting, then once a year.
Hematocrit is the main safety check. The guideline checks it at baseline, 3–6 months after starting and then yearly. Above 54% it stops therapy until the level falls, then restarts at a lower dose. Our hematocrit guide covers what drives it up.
PSA, for men who choose prostate monitoring. For men aged 55–69, or 40–69 at higher risk, the guideline checks PSA and does a rectal exam 3–12 months after starting. A rise of more than 1.4 ng/mL in the first year, a confirmed PSA above 4 ng/mL or an abnormal exam is a reason for a urology referral.
Some symptoms do not wait for the next lab. Chest pain, shortness of breath, swelling or pain in one leg, or a sudden change in mood are reasons to get medical care now. In the US call 911 for an emergency.
Frequently asked questions
How do I calculate my TRT dosage per week?
Work in the opposite direction from your per-injection dose: multiply the milligrams per shot by the number of injections per week. A 50 mg shot twice weekly is 100 mg per week; 30 mg every other day is about 105 mg per week, because every other day is 3.5 injections in a week rather than 3. The weekly total is the number your prescriber sets and the one your blood levels track.
How many units of testosterone is 100 mg?
It depends on vial concentration. On a U-100 insulin syringe, 1 mL = 100 units. At 200 mg/mL, 100 mg is 0.5 mL = 50 units; at 100 mg/mL it is 1 mL = 100 units; at 250 mg/mL it is 40 units. Enter your concentration above for the exact figure.
Is 100 mg or 200 mg per week the standard TRT dose?
There is no single standard. The Endocrine Society guideline lists 75–100 mg a week of cypionate or enanthate, or 150–200 mg every two weeks. The US cypionate label allows 50–400 mg every two to four weeks. Prescribers then adjust the dose to symptoms and lab results: the American Urological Association guideline aims for a total testosterone in the middle of the normal range, 450–600 ng/dL. Two people on the same weekly dose can land at very different blood levels. Your prescriber sets the total; this page only splits it and converts it to units.
Does injecting more often increase my testosterone levels?
No. The same weekly total split across more injections does not change weekly exposure, and average levels stay roughly the same. What changes is the shape of the curve – the gap between peak and trough narrows. That is why people who feel good for a few days after a weekly shot and flat afterwards often move to twice-weekly or every other day.
How do I split a weekly testosterone dose?
Divide the weekly dose by injections per week, then convert to units at your vial's concentration. The chart above has five weekly totals from 100 to 200 mg already worked out across four schedules and three concentrations.
What size syringe should I use for TRT?
Most people draw with a U-100 insulin syringe, where 100 units = 1 mL, because typical TRT volumes are 0.1–0.5 mL and that is hard to measure on a 3 mL syringe. Testosterone is viscous, so a larger-gauge needle is often used to draw and a finer one to inject. Every unit figure here assumes U-100.
How many mg is 30 units of testosterone?
On a U-100 insulin syringe, 30 units is 0.3 mL. At 200 mg/mL that is 60 mg; at 100 mg/mL it is 30 mg; at 250 mg/mL it is 75 mg. Switch the calculator to "Units drawn" to convert any other amount.
Is testosterone cypionate or enanthate better for TRT?
Neither. They behave very similarly on a schedule, so the same weekly total and the same injection frequency work for either. The practical differences are the oil they come in (cottonseed for Depo-Testosterone, sesame for US enanthate vials) and how much testosterone a milligram carries: about 70% for cypionate and 72% for enanthate, so switching at the same milligram dose changes the testosterone delivered by about 3%. Which one you use is your prescriber's decision.
Sources
The dose ranges, monitoring schedule, product details and half-lives on this page come from these. The splitting and unit conversion are arithmetic and need no citation; the peak-and-trough points follow from general pharmacokinetics rather than one paper. Testosterone content by weight is the ratio of molecular weights (testosterone 288.4, enanthate 400.6, cypionate 412.6, from PubChem). The guideline's Table 9 prints 24.5 and 14.1 nmol/L beside 600 and 350 ng/dL; at the conversion factor it uses elsewhere (0.0347) those are 20.8 and 12.1, which is what this page uses.
- Bhasin S, et al. Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2018;103(5):1715–1744. doi:10.1210/jc.2018-00229
- Mulhall JP, et al. Evaluation and Management of Testosterone Deficiency: AUA Guideline. J Urol. 2018;200(2):423–432. doi:10.1016/j.juro.2018.03.115
- Depo-Testosterone (testosterone cypionate injection) prescribing information, Pfizer. DailyMed
- Testosterone enanthate injection, USP prescribing information, Hikma Pharmaceuticals USA. DailyMed
- Xyosted (testosterone enanthate) injection prescribing information, Antares Pharma. DailyMed
- Bi Y, Perry PJ, Ellerby M, Murry DJ. Population Pharmacokinetic/Pharmacodynamic Modeling of Depot Testosterone Cypionate in Healthy Male Subjects. CPT Pharmacometrics Syst Pharmacol. 2018;7(4):259–268. doi:10.1002/psp4.12287
- Behre HM, Baus S, Kliesch S, Keck C, Simoni M, Nieschlag E. Potential of testosterone buciclate for male contraception: endocrine differences between responders and nonresponders. J Clin Endocrinol Metab. 1995;80(8):2394–2403. States the 4.5-day enanthate half-life as background, citing earlier work. doi:10.1210/jcem.80.8.7543113
Related TRT calculators & guides
- Steroid cycle calculator, plan several compounds across one timeline instead of a single weekly dose.
- Testosterone microdosing calculator, daily and every-other-day splits with the peak-to-trough figure.
- TRT timeline, how long each effect takes and when a blood test starts to mean something.
- TRT protocols compared, dosing and frequency across once-weekly, twice-weekly, and daily microdosing.
- TRT injection schedule, how often to inject by ester with sample weekly schedules.
- TRT injection guide, where to inject, technique, and site rotation.
- Testosterone cypionate tracker, log doses, auto-rotate sites, and track bloodwork in OptiPin.
- Low testosterone quiz, check your symptoms before starting a protocol.