Capacitor size

A few Panasonic Aluminum Electrolytic Capacitors (all have diameter 18mm, length 35.5mm = 1.78e-05 m^3):

C [mF]	V [V]	CV	CV^2/2	CV/volume [mFV/m^3]	CV^2/(2*volume) [J/m^3]
22.0	6.3	139	437	7.8e+03	2.5e+07
15.0	10.0	150	750	8.4e+03	4.2e+07
10.0	10.0	100	500	5.6e+03	2.8e+07
6.8	25.0	170	2125	9.5e+03	1.2e+08
4.7	35.0	164	2879	9.2e+03	1.6e+08
3.3	50.0	165	4125	9.3e+03	2.3e+08
2.2	63.0	139	4366	7.8e+03	2.5e+08
1.0	100.0	100	5000	5.6e+03	2.8e+08

For ceramic capacitors, most (all) datasheets only contain a small range in V or C, so I did a search on farnell specifying case-style=1206, tolerance=10%, material=X7R, Temp=125C, and then searched the highest capacitance for each max Voltage, resulting in:

C [uF]	V [V]	CV	CV^2/2	CV/volume [mFV/m^3]	CV^2/(2*volume) [J/m^3]
22	6.3	0.1	0.4	4.3e+04	1.4e+08
22	10.0	0.2	1	6.9e+04	3.4e+08
10	16.0	0.2	1	5e+04	4e+08
10	25.0	0.2	3	7.8e+04	9.8e+08
4.7	50.0	0.2	6	7.3e+04	1.8e+09
1	100.0	0.1	5	3.1e+04	1.6e+09
0.1	200.0	0.02	2	6.2e+03	6.2e+08
0.068	500.0	0.03	8	1.1e+04	2.7e+09
0.033	630.0	0.02	7	6.5e+03	2e+09
0.022	1000.0	0.02	1e+01	6.9e+03	3.4e+09
0.001	2000.0	0.002	2	6.2e+02	6.2e+08

The volume was calculated using: 1206; L=3.2mm, W=1.6mm, T=0.8mm..1.6mm (mostly 1.0m), M_MB=0.6mm, v=2mm*1.6mm*1.0mm=3.2e-9m^3 1856565RL http://www.farnell.com/datasheets/1662086.pdf