One way to determine your frame size is to use your own judgement.  Here is how to do that:

Compare your weight with the “ideal” weight in the Metropolitan Life Insurance tables.  If you are overweight according to the medium frame column in the chart, then you must have a large frame.  If you are overweight according to the large frame column, then you must have a REALLY, UNUSUALLY large frame: friend, you are big-boned.  Warning: this method is not very accurate, but it may make you feel a little better for a while.

A less biased way to determine your frame size is to measure your elbow, and use that measurement to look-up your frame size in the Metropolitan Life Insurance Company chart.  Here is how to measure your elbow:

1. Extend your arm in front of your body bending your elbow at a ninety degree angle to your body so that your forearm is parallel to your body.
2. Keep your fingers straight and turn the inside of your wrist towards your body.
3. Place your thumb and index finger on the two prominent bones on either side of your elbow, then measure the distance between the bones with a tape measure or calipers.

After you’ve measured your elbow, compare that measuremnt with the values in the chart below. The chart lists elbow measurements for a medium frame. If your elbow measurement for your  height and gender is less than the number of inches listed: you have a small frame. If your elbow measurement for that particular height and gender is more than the number of inches listed: you have a large frame.