I'm 15days post op I had lipo on my admomen/trunk.How do I figure out my size and the compression I need?

I recommend following up with your physician about their specific suggested after care protocol. I have my patients wear compression for 3 to 6 weeks straight then overnight for 3-6 months after their procedure. I suggest adding hyperbaric oxygen and lymphatic massage along with your compression to help decrease swelling. To improve your final results, I also recommend adding Vanquish for further fat removal; truSculpt iD, Exilis, Forma, and Venus Legacy for additional skin tightening; and Cellutone / ZWave to make the skin smooth, remove scar tissue, and improve the skin’s appearance.
Keep in mind that it will take 6 to 12 months to see the final outcome. Best, Dr. Emer

Follow your plastic surgeon's advice.  Plastic surgeon preferences for compression garments and length of time to wear differ.  I typically ask patients to use an adjustable garment (which our practice provides) with multiple bands so that tension can be adjusted and the areas of liposuction are less likely to get a fluid collection. 
Kenneth Hughes, MD, ABPS Board Certified Plastic Surgeon
Los Angeles, CA

Generous1422I appreciate your concern, however it is going to take a while for your swelling to resolve after significant liposuction fat removal. Your elastic garment should be snug, but not uncomfortable and tight as the one you are describing. Please stop using it at once and ask your plastic surgeon for advice in choosing the next appropriate garment. Good luck.

Hello dear!!
Thanks for the question and provided information as well.
Each doctor has their own protocol It is very important that you talk to him and follow his instructions.I suggest my patients to try the lymphatic massages and to use a full body compression garment, 24/7 for the first 3 months, and after that, for 12 hours a day for 3 more months, to get the best results.
It is important for the compression garment to be very tight, for it to help with the swelling, after surgery.
If you have any concerns, please follow up close with your plastic surgeon.
Good luck :)

I would suggest contacting your surgeon and ask what they prefer. They may even have you come in to try on garments.