Is it okay to have an implant that is narrower than my chest?

Not only is it ok, but it is the correct way of sizing implants. Proper sizing needs to account for the tissue that is already there, so that thickness must be subtracted from the measured base width in order to choose the right implant base diameter. Choosing an implant that is the same as the measured width will end up with an expansion of the breast laterally onto the chest and an oversized look, or it will result in a pocket that is too narrow for the implant and an oval shaped breast. Hope that helps!

Each plastic surgeon will have their own way of judging what our appropriate implants in regards to breast implant diameter.
It’s not at all necessary to have an implant that is as wide as your breast is.
If your implant is as wide as your breast than the implant will expand and make your breast even wider than it currently is.
If the implant is placed under the muscle, then it needs to fit under the pectoralis muscle, which doesn’t have that much to do with your breast diameter.
It’s generally technically easier to use a narrow implanted than a wide one.
This is especially true when using excessively large implants.
As long as you’re using modest size implants, then the chance of getting a good outcome is high.
You didn’t include pictures of yourself so we don’t know what your candidacy for the procedure.
Generally, speaking anytime, excessively large implants are used the chance of undesirable side effects, complications and need for revision surgery will always go up.
Would you describe it? Seems like a very appropriate way to go.
There are a lot of variables to take in the consideration, and there are different ways of measuring breast diameter.
Best,
Mats Hagstrom MD.