"Big Boned" use to be a euphamism or excuse for heavy, but people really do have differently sized skeletons! Knowing your frame size is much more helpful in figuring out a healthy body weight than something like BMI. Especially if you have a large frame those "averages" don't apply to you and will tell you to be much smaller than is healthy or reasonable. I made an infographic (attached) to help you determine your frame size and use the Hamwi formula to find your happy, healthy weight!
For some more good reading on this check out Livestrong.com (I have no affiliation with them)