To determine the body frame size measure the wrist with a tape measure and use the following chart to determine whether the person is small medium or large boned. If they touch you are medium framed.

Ideal Weight Charts For Men
What is large frame of body. People with large frames have a bone structure which is much larger therefore the weight of their bones is also more as compared to the weight of the bones of medium sized people. Its easy to confuse big frames with fatness but the two are usually really different. A smaller breadth measurement indicates a small bone structure while a larger measurement reveals that you have a large body frame size. Ectomorphs are skinny and long limbed with typically little muscle or body fat. Women under 52 large frame means a wrist size over 575 52 55 large frame means a wrist size over 625 55 or greater large frame means a wrist size over 65. In general you can use this calculation to determine an ideal body range.
The sizes are categorized into three categories small frame medium frame and large frame. Add 10 percent for a large frame size and subtract 10 percent for a small frame size to the ideal weight calculator. Assess your frame size according to the following chart. On the other hand the bone weight of the person with smaller bone structure is much lesser. If your fingers overlap an estimate for your frame size is a small frame. If you can barely get them to touch or they are not touching you have a large frame.
Equally obviously men and women have different structures. Bone mass and muscle mass all play a part in determining your optimal weight. Height under 52 small wrist size less than 55 medium wrist size 55 to 575 large wrist size over 575 height 52 to 5 5. For women 5 foot 2 inches to 5 foot 5 inches tall a wrist size of 6 inches or less is considered small framed 6 to 625 inches is medium framed and 625 inches or greater is large framed. Use your frame size to determine how losing weight will affect how you look. I recommend doing a combination of these measurements get a better idea of your frame size.
Once you know your wrist size compare it to your height to determine body frame size. One easy way to determine your body frame size is to wrap your thumb and major fingers around the smallest part of your wrist. If you naturally have a large frame certain parts of your body such as your shoulders will remain relatively large no matter how much weight you lose. The reason for this is that obviously bone structures vary in size and density from person to person. If your fingers do not touch an estimate for your frame is a large frame. A large body frame is a skeletal structure that is bigger wider or denser than average.
A person with a larger frame often stands taller and is broader than his or her peers. If your fingers just touch an esimate of your frame is a medium frame.