Convert from palmo [Portuguese] to caliber

Unit Definition (palmo [Portuguese])
The palmo is a traditional unit of distance in Spain and Portugal. The Portuguese palmo equals 0.1 braça or about 22.0 centimeters (8.66 inches). These units are based on the width of a person's outstretched hand, from the tip of the thumb to the tip of the little finger, a definition identical to that of the English span.

Unit Definition (caliber)
The caliber is a unit used to express the bore diameter of a gun. Traditionally, the diameter is stated in inches, so that ".22 caliber" refers to a pistol having a bore of 0.22 inches (5.588 mm). So the caliber is actually equivalent to the inch. The usage of the term "caliber" is actually now in decline, because bore diameters of many guns are now stated in millimeters. "Caliber" is the American spelling; elsewhere the unit is often spelled "calibre."