A solution at 4 mg/mL
Every conversion on this page is a division by 4 mg/mL. At this strength a 500 mcg amount is 0.125 mL, which reads as 12.50 units on a U-100 barrel.
Educational arithmetic only. Not medical advice and not a dosing protocol.
| Amount | Volume, mL | Volume, µL | U-100 | U-50 | U-40 |
|---|---|---|---|---|---|
| 50 mcg | 0.013 | 13 | 1.25 | 0.63 | 0.50 |
| 100 mcg | 0.025 | 25 | 2.50 | 1.25 | 1.00 |
| 125 mcg | 0.031 | 31 | 3.13 | 1.56 | 1.25 |
| 200 mcg | 0.050 | 50 | 5.00 | 2.50 | 2.00 |
| 250 mcg | 0.063 | 63 | 6.25 | 3.13 | 2.50 |
| 300 mcg | 0.075 | 75 | 7.50 | 3.75 | 3.00 |
| 500 mcg | 0.125 | 125 | 12.50 | 6.25 | 5.00 |
| 750 mcg | 0.188 | 188 | 18.75 | 9.38 | 7.50 |
| 1 mg | 0.250 | 250 | 25.00 | 12.50 | 10.00 |
| 2 mg | 0.500 | 500 | 50.00 | 25.00 | 20.00 |
Before you act on that number
This is educational arithmetic on figures entered by the reader. It is not medical advice, not a dosing protocol, and not a recommendation that anything be prepared, obtained or administered.
Nothing here states what quantity is appropriate for anyone, and there is no function in it that produces an amount to administer. A question about anyone’s health belongs with a licensed clinician who can examine the person asking.
Compounds of the kind this arithmetic is used on are largely research chemicals that are not approved by the FDA for human use. An exact calculation is not an accurate measurement: what is actually in a syringe depends on the preparation and the device, neither of which this page can see.
No qualified clinical reviewer is recorded against this site, and no credential is claimed anywhere on it. what this is not, at full length.
What is particular to this strength
What a 20 mg vial reaches in 5 mL, or a 10 mg vial in 2.5 mL. Strong enough that the small end of the amount range starts producing draws under five units, where half a graduation is over a tenth of the measurement. The table flags nothing - it is just arithmetic - but the first three rows are where the reading error is doing real damage.
Four milligrams per millilitre is 4,000 mcg/mL, so a 100 mcg amount is 25 microlitres: two and a half units on a U-100 barrel.
How to read the table
Find the amount in the first column and read across. The second and third columns are the same volume in different units, because millilitres are what a barrel is calibrated in and microlitres are what a small draw is comfortably described in. The last three columns are that volume on three barrels.
Only three barrels appear rather than five. The 0.5 mL and 0.3 mL U-100 barrels read identically to the 1 mL one - the calibration is the same and only the ceiling differs - so a reading of 20 units is 20 units on all three, and whether it fits is a question about capacity rather than about this conversion.
What this page assumes about your solution
That it really is at 4 mg/mL. Every figure here follows from that one premise, and nothing on this page can check it. If the strength was worked out by dividing a vial mass by the diluent poured in, it is a ceiling rather than a measurement, and every volume in the table is correspondingly a floor.
That matters more than any rounding. Why a derived strength is a ceiling works through where the gap comes from, and vial into a strength is the page that computes a strength with the right label attached.
The same conversion, a different way in
- The calculator itself
Any strength and any amount, rather than the ten tabulated here.
- The other seven strengths
Same ten amounts, divided by a different number.
- Starting from a vial instead
Twelve vial-and-diluent pairs, for a solution you mixed yourself.