Vial to Units

0.1 mg to units

0.1 mg is 4 units on a U-100 insulin syringe when the vial is 2.5 mg/mL, and 2 units at 5 mg/mL. The answer changes with concentration: units = mg ÷ mg/mL × 100.

0.1 mg in units, by concentration

Find the concentration of your vial in the left column. If you do not know it, divide the mg in the vial by the mL of water added.

ConcentrationVolume0.1 mg =
1 mg/mL · 5 mg vial + 5 mL0.1 mL10 units
2 mg/mL · 10 mg vial + 5 mL0.05 mL5 units
2.5 mg/mL · 5 mg vial + 2 mL0.04 mL4 units
3 mg/mL · 15 mg vial + 5 mL0.03333 mL3.333 units
5 mg/mL · 10 mg vial + 2 mL0.02 mL2 units
7.5 mg/mL · 15 mg vial + 2 mL0.01333 mL1.333 units · too small to read reliably
10 mg/mL · 10 mg vial + 1 mL0.01 mL1 unit · too small to read reliably
15 mg/mL · 30 mg vial + 2 mL0.006667 mL0.6667 units · too small to read reliably
20 mg/mL · 20 mg vial + 1 mL0.005 mL0.5 units · too small to read reliably

0.1 mg in units, by vial size and water added

The same conversion, starting from what is printed on the vial and how much bacteriostatic water went in.

Vial1 mL water2 mL water3 mL water
2 mg5 units10 units15 units
5 mg2 units4 units6 units
10 mg1 unit · too small to read reliably2 units3 units
15 mg0.6667 units · too small to read reliably1.333 units · too small to read reliably2 units

Calculate for your vial

The amount is filled in. Add your vial size and the water added.

mg
mL

Enter the vial size and the water you added.

Arithmetic only. This tool does not recommend a dose; use the one your prescriber gave you.

Questions

How many units is 0.1 mg?

It depends on the concentration of the vial. At 2.5 mg/mL (5 mg vial + 2 mL) 0.1 mg is 4 units on a U-100 insulin syringe. At 5 mg/mL (10 mg vial + 2 mL) it is 2 units.

Why is there no single answer for 0.1 mg in units?

Units measure volume: 100 units is 1 mL. Milligrams and micrograms measure the amount of substance. The link between them is the concentration, which is set by how much water was added to the vial.

How many mL is 0.1 mg?

Divide 0.1 mg by the concentration in mg/mL. At 2.5 mg/mL that is 0.04 mL; at 5 mg/mL it is 0.02 mL.

How many mcg is 0.1 mg?

0.1 mg is 100 mcg. There are 1,000 mcg in 1 mg.

What if 0.1 mg comes to less than 2 units?

Below about 2 units the marks on an insulin syringe are too coarse to read reliably. At 7.5, 10, 15 and 20 mg/mL, 0.1 mg is under 2 units. A weaker mix (more water in the same vial) makes the same amount a larger, easier volume to read.

The same amount written the other way: 100 mcg to units.

Nearby conversions

Calculators with vial-size presets