TCW illustrated field note · 18
mg → mL → U-100 markings
A companion to Vial Math. Arithmetic, not a dose recommendation.
The guide, in text
Concentration
mg/mL = total medication mass in mg ÷ final solution volume in mL.
Volume
mL = prescribed amount in mg ÷ concentration in mg/mL.
U-100 markings only
Syringe units = mL × 100. This does not apply to every syringe or pen.
Volume reference
0.05 mL = 5 units • 0.10 mL = 10 units • 0.50 mL = 50 units on U-100.
Check before measuring
1 mg = 1,000 mcg. Confirm concentration, syringe type and capacity with your pharmacist.
Sources + context
Source review: September 2026. Illustrations explain concepts; they do not verify products or replace individualized advice.