I would like a rounder bigger look - is 296cc too small? (photos)

You would need to be examined in person to determine the size that would be best for your anatomy. The size and placement of the implant has a lot to do with possible complications. The key to this surgery is to select an implant that is not so large that the muscle cannot cover it reliably. You want a nice result, but you want to avoid the complications (need for removal, infection, extrusion, fluid collection, implant migration, implant visibility, and capsular contracture among others). Studies have demonstrated that sizes above 350 cc have a greater rate of complications, but most women choose an implant volume in the 350cc to 400cc range. The intramuscular placement also reduces the risk for capsular contracture and sciatic nerve damage.

You may be able to go with a larger size but an in-person consultation is necessary to know for sure. Please be sure to choose a board-certified plastic surgeon who specializes in this procedure and is well known for their work in the medical community.

Based purely upon your photos, a Stanton Anatomic™️ buttock implant size 400 cc or 450 cc may serve you best. However, please keep in mind that an in-person physical exam is always first necessary before providing any final surgical recommendations. Please read on.
Other than placing buttock implants within the gluteus maximus and medius muscles (aka “intramuscular”) NOT on top of the muscle
or “subfascial” or “dual plane”, the most important factors in creating the perfect derriere and/or hourglass figure with implants is indeed selecting the right size AND shape. I have found the best way to assure this is to simply measure the actual dimensions of the patient’s gluteus muscles (not butt cheek fat pad, which may appear “round”) and quantity and quality/density of these muscles. With these anatomical measurements, I can select an implant that not only significantly augments the buttock but also supplies the correct 3-dimensional enhancement to look as real as possible...with positional changes (eg. bending over and squatting down) and even in the most petite patients that have small/lean muscles and minimal overlying fat. The fact is, over 95% of the human population has a more oval shaped gluteus muscles not round. Therefore an oval shaped implant such as the Stanton Anatomic™️ buttock implant conforms best and produces a more realistic contoured outcome better than round implants. Contrary to what many think, a round implant placed correctly within the muscle actually sits up at the top of the butt cheek, creating an unnatural pointy or “gum-drop effect”, not at the lower part of the butt cheek and thus does not contribute to filling or rounding out of any of the lower buttock pole. Height and weight are considered but not nearly as relevant as the above measurements. Final note, because an extremely few number of board certified plastic surgeons specialize in buttock implants, you may have to travel away from your local area to seek consultation with this particular type of surgeon. Glad to help.