The following is reproduced from The Music Trade Review 85, 16 (October 1927) p. 27. It gives the standard dimensions for soprano, concert and tenor ukuleles — to help people tell the difference between ukuleles that are toys and those that are musical instruments. Enjoy…
1. Scale length (Distance from nut to bridge):
a. Standard Size Ukulele ………………. 13 to 13 3/4 inches
b. Concert Size Ukulele ……………….. 13 3/4 to 14 1/2 inches
c. Tenor Size Ukulele ………………….. 14 1/2 to 15 3/4 inches
2. Must not have less than twelve (12) frets.
3. Back must be curved or arched.
4. Body must not be less than 2 inches deep at the lower bout.
5. Top of sound board must be of one-twelfth (1/12) inches veneer, approximately.
6. Frame or sides must be lined.
7. Sound-hole must be trimmed with celluloid or inlaid purfling.
8. Ribs must be sanded or finished off smooth.
9. Frets, after correct regulation, must be slightly rounded, to enable the player to execute the glissando without cutting fingers or strings.
10. Height of strings:
a. Above top edge of first fret must be not less than one-thirty-second (1/32) inch nor more than three-sixty-fourths (3/64) inch.
b. Above top edge of twelfth fret must be not less than one-eighth (1/8) inch nor more than five-thirty-seconds (5/32) inch.