IV Drip Rate Calculations
Drop by ML by CC

Congratulations! You are now ready to move onto IV drip rate calculations. If you have not already learned how to give the correct number of pills or measure the right amount of an IV push medication please go back and do so now.

When patients are admitted to the hospital, it is always a possibility that they will need an IV drip. It is important that you know how to do these rate calculations, so that you can assure they are not giving too much or too little of a drug. It is feasible that you can be responsible for serious harm, or even death, if you do not master this type of calculation.

We will be adding on to the previous formulas you have learned. IV drip rate calculations may require a few extra steps, however the basic process is the same as you learned how to calculate liquid medication dosages.

1. Set up the equation
2. Cancel the like units
3. Do your basic multiplication and division

There are a few things to remember when setting up your equations for IV drip rate calculations.

• Your answers will always be in mL/hr. That is what IV pumps understand
• You may need to add extra column depending on the information you have. This will be for conversion purposes, such as minutes to hours or micrograms to milligrams
• If you have a 1 liter bag, automatically change that to 1000 mL
• mcg doses are usually written as mcg/min
• If your answer seems CRAZY..like 1500ml/hr...You probably set up your equation wrong, double check all your units!

Here are your formulas

Here are your free examples

You have a bottle of Amiodarone with 900mg/500ml. You have given the loading dose bag and now need to start the gtt at 1mg/min. How fast should you run the drug?

  500 mL  X   1 mg   X   60 min  ═ 54,000 mL ═ 33.3 ml/hr
  900 mg      1 min        1 hr         900 hr

And another

Your chest pain patient has an order to start a Nitroglycerin gtt at 15mcg/min. Your bag has 50mg/500ml. How fast should you run your medication?

  500 mL  X   1 mg    X   15 mcg  X   60 min  ═ 450,000 mL ═ 9 ml/hr
  50 mg      1000 mcg       1 min        1 hr        50,000 hr

Keep Going!

You have vancomycin to give to you patients. Let’s say it is safe to give 500mg over 1 hour. You have a bag of 750mg/500ml to give. At what rate will you give this bag, and how long will it take the bag to completely infuse?

  500 mL  X   500 mg   ═ 250,000 mL ═ 333 ml/hr
  750 mg        1 hr            750

NOW
How long will that take?

  1 hr  X   500 mL     ═ 500 mL ═ So this should take 1.5 hours
333 mL        1            333

Very soon you will be learning how to calculate weight-based IV drips. Until that time, continue to practice what you have learned already. I found a great site that reinforces how to use this method for IV drip rate calculations.

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