How to Read a Syringe (The Right Way)

Do you know how to read a syringe? Whether you’re a medical student or someone who’s merely curious, knowing how to read one correctly isn’t as straightforward as you’d think.

You might believe that just by looking at the lines of the tube you can easily gauge how much liquid is inside. You’d be wrong. 

Learn about a few different types of syringes and how to read and dose them the right way.

Types of Syringes

As a nurse, you will come across five different types of syringes. All types have an adapter, barrel, scale, plunger seal, and plunger. 

The 10 mL has markings to measure every 0.5 mL and has a capacity of 10 mL. A 5mL syringe has lines to indicate every 0.2 mL up to 5 mL. 3 mL syringes go by increments of 0.1 mL.

The 1 mL syringe has markings on the barrel for every 0.01 mL. Lastly, the markings on the 100 unit insulin syringe each measure two units.

How to Choose a Syringe

Use smaller volume syringes for injections that are subcutaneous and intramuscular. Smaller syringes have higher pressure flows. 

10 mL through 12 mL syringes are used for catheters, medical tubes, and central lines. Larger syringes such as the 20 mL through 70 mL are meant for irrigation.

How to Read a Syringe

After choosing which syringe is best for your current needs, you have to accurately measure the liquid. Reading a syringe is critical.

  1. Hold Flange

Grab the syringe by the flange, not the barrel. Doing this prevents you from covering up the markings when measuring syringe doses. 

  1. Fill Syringe

Fill the syringe past the desired amount. Do this by pulling back on the plunger until you have about 2mL excess liquid.

  1. Measure

Slowly loosen your grip on the plunger until the liquid you’re measuring hits the mark on the barrel that indicates the amount you need.

  1. Double Check Measurement

Start reading from the tip of the plunger. The top ring is the part that touches the liquid you’re measuring. Ignore the area of the plunger that isn’t touching the liquid, it’s irrelevant for measuring.

Depending on the size syringe you’re using count the marks until you hit the tip of the plunger and calculate how much liquid you have.

How to Dose a Syringe

When using a syringe, make sure you have the plunger pressed down to the end of the barrel. Draw back the plunger once you’ve placed the tip in the liquid. Look at the markings on the barrel to see how much liquid you have.

If the liquid you’re measuring needs to have impurities removed, you need a syringe filter. Visit and choose from a variety of syringe filters.

Learn More about Syringes

Now that you know how to read a syringe the right way, you can use them with accuracy. No more second-guessing yourself and dosing incorrectly. 

Before you use a syringe to measure doses, you should test yourself. Take a quick and short quiz you can take to make sure you understand all the points covered above.

If you enjoyed reading about syringes, check out our Health page! We post articles about basic health and fitness that can guide you to having an improved mental and physical life.

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