How to determine the scale length or string length of a Violin, Viola, Fiddle, Cello or upright Bass
PLEASE READ ALL INSTRUCTIONS CAREFULLY BEFORE PROCEEDING. THESE INSTRUCTIONS APPLY TO VIOLIN, VIOLA, FIDDLE, CELLO AND UPRIGHT BASS.
If you are not familiar with how to properly position your bridge, please consult a qualified violin maker, knowledgeable instructor, trained sales person or experienced player to assist you the first time. A few moments of instruction can help prevent accidentally making your Violin, Viola, Fiddle, Cello or upright Bass unplayable.
The bridge is located between the fingerboard and tail piece of the instrument. The bridge has grooves filed in it to "cradle" the strings. It holds the strings up off the body of the instrument and is made of wood. The f notches are tiny v shaped notches mid-way on each side of the f holes (see image above).
After the bridge has been properly positioned, measure between the second and third strings from the fingerboard side of the nut to the top of the bridge. The nut is a black piece of bone or acrylic attached at the top end of your fingerboard, between the peg box and the fingerboard (see image above). It has small grooves filed in it to "cradle" the strings. You are measuring the effective vibrating length of the strings. This is also known as the scale length or string length of the instrument.
A properly positioned bridge will always insure that your instrument has the correct scale length and tone intervals. Below is a list matching scale length with Violin (Fiddle), Viola, Cello and upright Bass sizes. This list is based on the modern day full size (4/4) Violin having a body length of 14 inches or 356mm, a 4/4 Viola body of 17 inches or 430mm, a 4/4 Cello body of 29-3/4 inches or 755mm and an upright 4/4 Bass body of 45-5/8 inches or 1160mm*.
Stringed instruments over the centuries have varied in size and scale length. Modern era violin makers adhere to accepted industry standards. If your instrument is old rely on a properly positioned bridge as the determiner of your instruments scale or string length.
Here is a link to convert millimeters to inches:
For best results and the most precise string lengths use the millimeter measurements. Some of the standard inch measurements have been rounded up or down for convenience.
Violin Scale or String Lengths:
4/4 Violin = 330mm = 13 inches
7/8 Violin = 317mm = 12½ inches
3/4 Violin = 310mm = 12¼ inches
1/2 Violin = 285mm = 11¼ inches
1/4 Violin = 260mm = 10¼ inches
1/8 Violin = 235mm = 9¼ inches
1/16 Violin = 215mm = 8½ inches
Viola Scale or String Lengths:
4/4 Viola = 390mm = 15 3/8 inches
3/4 Viola = 375mm = 14¾ inches
1/2 Viola = 355mm = 14 inches
1/4 Viola = 330mm = 13 inches
1/8 Viola = 310mm = 12¼ inches
1/16 Viola = 285mm = 11¼ inches
Cello Scale or String Lengths:
4/4 Cello = 695mm = 27 3/8 inches
3/4 Cello = 635mm = 25 inches
1/2 Cello = 600mm = 23½ inches
1/4 Cello = 535mm = 21 inches
1/8 Cello = 490mm = 19¼ inches
Upright Bass Scale or String Lengths:
4/4 Bass = 1100mm = 43 1/3 inches
3/4 Bass = 1060mm = 41¾ inches
1/2 Bass = 975mm 38 1/3inches
1/4 Bass = 900mm = 35½ inches
*Many thanks to Henry A. Strobel and his excellent book "Useful Measurements for Violin Makers, A Reference for Shop Use" for providing the above scale length millimeter measurments.