Amount to volume
The measurement step, for one of the draws the vial arithmetic counted. Give the strength of the solution and the amount, and get the volume and the barrel reading.
Educational arithmetic only. Not medical advice and not a dosing protocol.
Enter the figures above.
Where that comes from
- Amount into volume:
volume = amount ÷ strength. 250 mcg out of a 2.5 mg/mL solution is250 ÷ 2500 = 0.1 mL, because 2.5 mg/mL is 2,500 mcg/mL. - Volume into amount is the multiplication:
amount = volume × strength. - The barrel reading is the volume times the calibration:
units = mL × units per mL. A tenth of a millilitre is 10 units on a U-100, 5 on a U-50 and 4 on a U-40. - Both mass units are converted explicitly before anything is divided, because assuming they match is how an answer ends up out by a factor of a thousand.
Why this worksheet is on a site about repeats
Because the vial arithmetic counts draws and says nothing about whether any one of them can be measured. A 10 mg vial holds a hundred 100 mcg draws, and at 10 mg/mL each of those draws is ten microlitres: one single unit on a U-100 barrel, where half a graduation is half the measurement.
The count and the measurability are independent, and both have to work. This worksheet is the second half of that check, and vial to strength is where the strength it needs comes from.
What the strength figure assumes
That it is right. This worksheet takes the strength as given and cannot check it. If it was derived by dividing a vial mass by the diluent poured in, then it is a ceiling rather than a measurement - the dissolved solid takes up room, so the finished solution is larger than the diluent - and every volume derived from it is correspondingly a floor.
The worksheet on vial to strength carries that label properly, and exact and approximate covers which figures on this site are which.