How much smaller will my arms be after liposuction?

You need to be seen to determine if liposuction is an option for you. Liposuction works When the skin is in excellent condition and the arm is not very big. A brachioplasty is necessary to reduce excess skin in many cases.

Without an exam, it will not be possible to fully evaluate you and give you recommendations. Be sure to discuss your goals and concerns with your board certified plastic surgeon and consider the pros and the cons. Be certain your surgeon is properly certified.  I've attached a link where you can start your search. 

Hello and thank you for your question.  The
best advice you can receive is from an in-person consultation.  It would be helpful to view a picture of your arms in order to answer your question accurately.   Make sure you specifically look
at before and after pictures of real patients who have had this surgery
performed by your surgeon and evaluate their results.   The most
important aspect is to find a surgeon you are comfortable with. I recommend
that you seek consultation with a qualified board-certified plastic surgeon who
can evaluate you in person.
Best wishes and good luck.
Richard G. Reish, M.D.  FACS
Harvard-trained plastic surgeon

The results of a liposuction procedure dependent on the amount of skin present and the quality (elasticity) of the skin.  It is not possible to give you a measurement that you can expect. Best wishes.

Everhopeful12.  Photos would be helpful to assess amount of redundant skin present within your upper arms. Also the quality of skin, and amount of elasticity contributes to the final result after liposuction of the upper arms. If skin quality is good, you can expect reasonable improvement. Be sure to consult with a board certified plastic surgeon. Good luck!

It is difficult to estimate how small your arms will become after the procedure. Each individual has different amounts of fat and would have different results.Your best resource of information would be your surgeon, as he/she will know your condition best.  

It is unlikely that the circumference would reduce by that amount, and if it did you would possibly be left with loose skin.  Discuss with your surgeon for realistic expectations.  All the best

Dear Everhopeful12,A 3 inch reduction in your arm circumference is not realistic, especially if you are starting at only 14 inches.  That would be along the outer extreme of expectations.  Good luck!

You probably can't find much information because we typically don't record our results based on dimension of the arms or circumference of the waist for example and I'm not aware of any study that has reported this data with arm liposuction. 
We tend to look at our results in a more subjective manner when it comes to liposuction of the arms and that is to increase the definition of the bicep, tricep and deltoids as well as obtain a flatter straighter line on the bottom aspect of your arm rather than a hammock shape. 
Ultimately we are more interested in the look of your arm after surgery than the size of your arm after surgery and that's why you can't find any good data or papers written about this.
Imagine if you are unhappy with how your arms looks after liposuction, but your surgeon said "oh yes sure it doesn't look that great, but hey, you arm circumference is 3 cm less then it was before surgery". 

This all depends upon how much fat is surrounding your underlying architecture. Reducing the total volume will generally improve the overall circumference.