Some syringes, such as those used to measure insulin, are marked in numbers of “units” rather than milliliters. Some older or non-standard syringes may also use different units.

Each of the smallest lines would count for 0. 2 milliliters (0. 007  fl oz). For instance, the first line above the 2 milliliters (0. 068  fl oz) line would equal 2. 2 milliliters (0. 068  fl oz), the second line above it would equal 2. 4 mL. The mid-sized line halfway between each number would equal the odd number in between. For example, the halfway mark between 2 milliliters (0. 068  fl oz) and 4 mL equals 3 mL, and the mark halfway between 4 milliliters (0. 14  fl oz) and 6 mL equals 5 mL.

So, if you need to measure 2. 3 milliliters (0. 08  fl oz), draw the liquid to the third line above the 2 line. If you need to measure 2. 7 milliliters (0. 09  fl oz), that will be the second line above the 2. 5 mL mark. Your syringe may be marked in other increments, such as multiples of 5 milliliters (0. 17  fl oz) or in fractions of 1 milliliter (0. 034  fl oz). If so, the principle stays the same—just look for the major numbers marked on the syringe, and count the smaller marks in between.

For instance, say you have been asked to measure 3. 3 milliliters (0. 1  fl oz) of a medication, but your syringe Is marked in hash marks of 0. 2 milliliters (0. 007  fl oz) increments. Pull the medication up the syringe and then push the plunger down until the medication is between the 3. 2 milliliters (0. 1  fl oz) and 3. 4 mL lines.

Holding the syringe this way is also important for super-precise, scientific measurements, to ensure that your body heat from your fingers doesn’t distort the material you’re measuring in the syringe. For everyday measurements (like home medications), you don’t need to worry about body heat distortion.

For instance, if you are measuring out 3 milliliters (0. 10  fl oz) of a children’s medication, use a 5 milliliters (0. 17  fl oz) or larger syringe. Pull the plunger back until the liquid fills the syringe past the 3 mL mark.

For instance, if you are measuring 3 milliliters (0. 10  fl oz) of a medication, push the plunger down until it is even with the 3 mL mark.