How Large Should Your Cello Be?

If you go into any reputable shop that sells cellos, most of the new ones available will likely be somewhat larger than many of the 100-150 year old cellos. So what constitutes a large cello and does bigger cello mean bigger sound?

First let’s define average cello. Other people in the field may disagree but after looking at and measuring thousands of cellos of all ages and ilks for the past 20 years, I propose today’s “average size” cello. I’ll work in inches as most U.S. residents still use this system. Multiply these numbers by 25.4 if you want millimeters.

a) Length of body: 29 ¾.

b) Upper bout: 13 7/16.

c) Center bout: 9 1/2. d) Lower bout: 17 3/16.

e) Average rib height (rib height near neck + rib height near endpin, divided by 2): 4 ½.

The above measurements are for a Stradivari and similar models. Different models, like a Montagnana, widen the bouts and shorten the length. Which brings us to the concept of Body Volume – the interior space of the cello body. For you number people (I tend to be one) let’s define a formula for Cello Body Volume (don’t freak – I’ll walk you through this) as the length times width times depth. The width is a bit tricky as the shape of the cello isn’t rectangular or even regular, so let’s calculate the width by averaging the 3 bout measurements. Referring to the paragraph above: the width is (b+c+d)/3. It’s not perfect, but it is sufficiently accurate for comparison purposes.

To then calculate the body volume of our “average” cello we take the width as: 13 7/16 + 9 1/2 + 17 3/16 = 40 1/8. Dividing by 3 we get 13 3/8 which is our width. So our length 29 ¾, times our width 13 3/8, times our depth (rib height) 4 1/2 = (approx) 1791 cubic inches.

Montagnana and occasionally Gofriller models tend to have slightly more body volume. Even though their lengths are a bit shorter and their depth closer to 4 1/2, their average width is sufficiently larger to give them more volume. One I just measured equaled 1861 cu in.

A truly great playing cello is Melissa’s 1880’s German whose measurements are: length 29 ¼, bouts 12 3/8, 8 3/8, 16 ¼, and average rib height 4 3/8 giving it a body volume of only 1578 cu in. And yet it outplays most “average” size or larger cellos including in the lower register. How can this be true?

Some years ago at the request of a customer, we had a bass made for us that had a 7/8 –size body, but a ¾ string length (most basses are ¾). The idea was that the customer would be able to switch easily between this and his jazz bass as the two instruments would have the same string length but the larger body would give him a bigger, fuller sound for classical playing. Interestingly, other shops and companies almost instantly picked up on this idea, and for a short while it was almost impossible to acquire a ¾ size bass as most commercially available basses came in this new size. The interesting thing was that almost none of these basses sounded nearly as good as a regular ¾ bass. Why? Full 7/8 basses had the larger depth of sound one might expect: and the only consistent difference was the string length.

It seems that the vibrating length of the strings matching, in some way, the body volume is critical to the depth of sound we’re looking for in a larger instrument. When Rob Morse worked for us, he acquired a somewhat larger bass than the normal ¾ size but set his string length at ¾ length. When he experimented and set at the longer length the bass was actually made for, his depth of sound increased dramatically.

There are more variables in cello sound than probably anyone knows: but the body volume variable is tricky and without sufficient string length, a larger cello body may produce a much lesser sound than a smaller one – everything else being equal. Cello string length is pretty well fixed today: strings are manufactured to reach the proper tension at pitch with this fixed length. Longer lengths also mean longer distances between notes which in turn make speed more difficult.

Our experience is that most cellists inquiring about Montagnana models are looking for a bigger, deeper sound, and most inquiries about slightly smaller cellos have to do with physical issues: tendenitus or arthritis, small hands, etc. Interestingly, we have found over the years that older, smaller cellos will frequently outplay both older and newer larger cellos. Sometimes our given string length works better on less than “normal” size cello bodies than it does on larger ones.