Standard building specifications for the Viola;

Tuning c g d' a';
Note: all measurements are in millimeters

Size
SmallMediumLarge
CorpusLength
390
405
420
Width - Upper Section
188
193
198
Width - Middle Section
127
131
135
Width - Lower Section
228
236
244
RibsHeight
36
38
38
Thickness (average)
1.3
1.3
1.4
Building FormThickness
14
LiningsWidth
8
Thickness
2
Blocks (size)Upper
55 x 18
Lower
50 x 15
Upper Corners
12 x 24
Lower Corners
22 x 40
Arching HeightsBack
15
16
17
Top
16
17
18
Average Thickness (Back)At soundpost
4.0
4.5
5.0
End sections
2.4
2.7
3.0
Hollowed edge
2.2
2.3
2.4
Midsection
2.4
2.6
2.8
Edges
3.9
4.0
4.1
Average Thickness (Top)At soundpost
3.1
3.2
3.3
End sections
2.5
2.6
2.7
Hollowed edge
2.3
2.4
2.5
Midsection
2.5
2.6
2.7
Edges
4.1
4.2
4.3
EdgesOverhang from ribs
2.3
PurflingAverage distance from edge
3.5 - 4.5
Average width
1.2 - 1.3
F HolesLength
78
78
82
Distance apart at top
46
48
50
Distance from edge at lower end
13 - 15
Mensur (2:3 proportion)Top
219
225
231
Neck length
146
150
154
Bass Bar (after fitting 5:4/4:3)Average length
n/a
n/a
n/a
Width
5.5
6.0
7.0
Average height at center
13
14
15
FingerboardLength
290
295
300
Length of hollow
120
Width at nut
24
24
24.5
Width at bridge end
44
46
48
Thickness at center
9.3
9.5
9.7
Thickness at edges
5.5
6.0
6.5
Height above top (bridge end)
24
25
26
ScrollLength
122
125
128
Width at ears
46
NutThickness
5.5
5.5
6.0
SaddleLength
38
39
40
ButtonHeight
13
14
15
Width
22
22.5
23
PegboxWidth at nut (set out)
28.5
Width at throat
20
21
22
Length
80
82
84
PegsDistance apart at centers d - c
60
62
64
Distance apart at centers a - g
17
17
18
NeckHeight of foot (above top at purfling)
7.5
8.0
8.5
Angle with body
87°
Thickness at center
20/22
SoundpostThickness
6.0
6.5
7.0
BridgeWidth at foot
45
46
47
Thickness
5
Height
42
Angle of strings at bridge
157°
StringsWidth at nut
16.5
17.0
17.5
Width at bridge
35
36
37
Length (nut to bridge)
370
380
390
Distance above fingerboard (Steel)
c = 4.5, a = 3.0
Distance above fingerboard (Gut)
c = 5.0, a = 3.5