Pocket Watch Size Chart

Use the size chart below to determine the size of your watch by carefully measuring the pillar plate (dial side) diameter of the movement with a micrometer.

The sizing system utilized by American watch companies is derived from the Lancashire Gauge, popularized in the English watchmaking trade. One inch is taken as a basing figure and 5/30 of an inch is added for the fall or drop of the dial, resulting in 1 5/30 of an inch referred to as "naught size” (0s). Subsequently, the addition or subtraction of each 1/30” increment results in scaling the size up or down. For example, size 12 measures 1 17/30” (12 increments of 1/30” from the naught size of 1 5/30”).

Note: Companies did not strictly adhere to this sizing standard, using a 6/30" drop instead of the 5/30" for larger movements. As a result, “18 Size” American movements are actually 19 Size according to the Lancashire Gauge system.

E. Howard Size Chart

Early production at E. Howard & Co. was based on Edward Howard's sizing system rather than the Lancashire Gauge that was later adopted by the American watch industry. Howard's letter classification system was based on the letter "A" representing one inch in diameter. Each subsequent letter progressing through the English alphabet represented an incremented value of 1/16th of an inch. Due to these minor size differences, early watches produced at the E. Howard factory required special cases specifically sized using the Howard size guage.