Tools · TRT
TRT draw-volume calculator
By An NayalLast reviewed
Testosterone comes as an oil at a fixed concentration, so the only math is turning your dose in milligrams into a volume and the units on the syringe. Enter the dose and your vial strength to see the draw.
Draw this much
50units
= 0.5 mL at 200 mg/mL
Math conversion only. This does not tell you what dose to take. Always verify with a licensed provider. Testosterone is a controlled substance in many places.
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Worked example
The calculator opens with a 100 mg dose, a 200 mg/mL vial and a 1 mL syringe. Here is what it does with those numbers.
- Volume: 100 mg divided by 200 mg/mL is 0.5 mL.
- Units: 0.5 mL times 100 units per mL is 50 units. That is the big number in the result card, with "= 0.5 mL at 200 mg/mL" under it.
- Syringe check: 0.5 mL is less than the 1 mL barrel, so there is no warning and the bar fills to the halfway mark.
Now switch the syringe to 0.3 mL. The draw is still 0.5 mL, which is more than that barrel holds, so the bar fills and turns red and the tool says the draw needs 0.5 mL. Pick 0.5 mL instead and the draw fits exactly, with no warning, because the check only fires when the volume is larger than the barrel.
Change the concentration to 100 mg/mL and keep the 100 mg dose. The volume doubles to 1 mL, or 100 units, which fills a 1 mL syringe to the top.
How the math works
There are two steps, and both are unit conversions. First the dose is divided by the concentration printed on your vial to get a volume:
volume (mL) = dose (mg) / concentration (mg/mL)
Then the volume is converted to the marks on an insulin syringe. The tool assumes a U-100 syringe, which means 100 units per mL, so one unit is 0.01 mL:
units = volume (mL) x 100
Under the hood it reuses the same tested function as the peptide reconstitution calculator, with the vial treated as 1 mL holding your concentration, so the concentration passes straight through.
The result shows units to one decimal place and mL to three. If the volume is larger than the syringe you picked (0.3, 0.5 or 1 mL), the tool shows an over-capacity warning with the mL the draw needs. If the dose or concentration is empty, zero or not a number, it shows no result instead of a guess.
Concentration differs by product. Cypionate and enanthate are usually 200 mg/mL and propionate is often 100 mg/mL, but always use the number on your own vial.
Questions people ask
How many units is 100 mg of testosterone at 200 mg/mL?
50 units. 100 mg divided by 200 mg/mL is 0.5 mL, and on a U-100 insulin syringe 0.5 mL is 50 units, because U-100 means 100 units per mL.
How many mL is 200 mg of testosterone cypionate?
At 200 mg/mL, 200 mg is 1 mL, which is 100 units on a U-100 syringe. If your vial is a different strength, divide the dose by the mg/mL printed on it.
Are syringe units the same as mg?
No. Units on an insulin syringe measure volume (1 unit = 0.01 mL on U-100). How many mg a unit holds depends on the vial's concentration: at 200 mg/mL one unit holds 2 mg, at 100 mg/mL it holds 1 mg.
What happens if the draw is bigger than my syringe?
The calculator flags it as over capacity and shows how many mL the draw needs. It does not change the math. A 0.5 mL draw fits a 0.5 mL or 1 mL syringe but not a 0.3 mL one.
Pepteca is for education and information only. It does not provide medical advice, diagnosis, or treatment, and its calculators perform unit math only. Always verify with a licensed provider before starting, changing, or stopping any protocol. Many peptides are not approved for human use and may be regulated differently where you live.