# Help With Pharmacology Conversions

- 0Oct 17, '08 by LIZ110908Good Evening Everyone,

I am studying for the NCLEX and so far I have so much trouble with the math and conversion of ml, units, grams, grains, etc.... they just seem so confusing to me!!! Does anyone have a good and easier way that might help me remember how to calculate the conversions?? I can do the math just can't remember how to convert! - 4,916 Visits
- 1Oct 18, '08 by PEBBLES1I dont like using the decimal point so this is how I remember: if you are going from smaller to larger you divide by 1000 (SLD) or larger to smaller you multiply by 1000 (LSM) always remember you are going to divide by 1000 or multiply by 1000

Also, think about cocaine. a Kg is the largest it more than a gram and so on. this section you will multiply by 1000

(larger) 1kg = 1000Gm (smaller)

(larger)1Gm = 1000mg (smaller)

(larger)1mg = 1000mcg (smaller)

if you reverse it you will divide by 1000

if the math problem is in different systems you must convert ex:

orderd cipro0.3g Iv q12h. It's avail 400mg/ml. how many Ml's will the nurse prepare

step 1. convert grams to mg's: 0.3 x 1000= 300

step 2. do the math Desired is 300 mg divided by med on hand is 400ml per 1ml times the qualtinty.

300 divided by 400 the answer is 0.75mls

for the grains it's always 60 or 65 and you X by 10

ex: md orders 325mg of tylenol on hand is 65 grains of tylenol how many tablets will the nurse give.

step 1. 65 or 60 multiply by 10

65 X10 =650

then you divided 650 by 325 ans is 2 tablets

if you do 60 x 10 =600, then divide by 325 you will get a crazy answer like 1.846 so just round up to 2. I hope this help. good luck with the nclexLast edit by PEBBLES1 on Oct 18, '08 :**Reason**: forgot to add somenthinLIZ110908 likes this. - 1Oct 19, '08 by bayoufroggI always look at the problem and ask myself what is it asking. You will have to know the conversions, there is just no way around it but to memorize them. There is one useful thing that I find myself doing, that may be useful to someone else and has been to people I've explained it to. I notice a lot of people have trouble at when to DIVIDE versus MULTIPLY.

This may help. Look at the two units(G to Kg for example). Remeber this saying: If its BIGGER to SMALLER, the answer will be BIGGER. If its SMALLER TO BIGGER, the answer will be SMALLER. Lets take G to Kg. You know that Grams are smaller than Kg. So......say to yourself, "The question asks about a converting a SMALLER unit to a BIGGER unit, so the answer is SMALLER." Now you know that the answer will be smaller than the intial amount of Grams given in the problem, PLEASE DONT MULTIPLY!!!! You can only get smaller by dividing. Now you just have to know that there are 1000 units difference between grams and Kgs. You already know that is has to be smaller, so just divide 1000.

Hope this makes since. I do this at the beginning of EVERY problem I solve and its helpful to put things into perspective. Good luck!LIZ110908 likes this.