The only difference between figuring out ml/hr and gtt/min is one uses hours and one uses minutes *plus the drop factor*
The formula for ml/hr is: Total volume to be infused (say 2000 ml) / total time to be infused in hours (say 8 hours) = 250mls/hr. You have that one nailed you say.
Okay, gtt/min. The one difference with these questions will be that you will have to use one more component: the drop factor. If you use this equation, you use the drop factor. You may get the drop factor for ml/hr questions, but that's just pointless info. You learn to discern necessary info from questions.
So, this formula: Total volume to be infused (2000 ml) / total time to be infused in minutes (8 x 60min = 480min) = 4.1667 (don't round though. When using the calculator, just leave it and follow through the equation
) You have your 4.166666 for this equation. Say the drop factor is 20 (gtt). Times (x) that drop factor by your division answer (4.16666666). Round to the nearest whole number, and you have your gtt/min. gtt means drop.
So your answer is 83.333333, but you are doing drops. Drops have to be whole numbers. It would be 83 gtt/min. Granted, you probably wouldn't have that drop factor, but it was just an example out of my head.
Also, google is your best friend. Questions and help are out there. I hope you do well. Good luck
*if you need further explanation, just ask. I'll check back up on this topic*