Here are the stats on comparing various LCD monitor sizes and their native resolutions in terms of how it affects the size of characters (etc).
The operative spec to compare is “pixel pitch,” which is a direct measurement to enable you to compare character/etc sizes (assuming identical data being sent to the monitor, of course). The larger the pixel pitch the larger the character size. (Naturally, the higher the resolution the more the real estate, which is a separate matter.)
Here are the ones I looked at, listed both by monitor size and by pixel pitch. I compared the older 19" 4:3 to the common wide-screens.
Listed by monitor size and resolution (and with the % size compared to 19" 4:3, which is the largest of those I compared):
19" 4:3 = 1280 x 1024 = .294 pixel pitch (100%)
19" wide = 1440 x 900 = .285 pixel pitch (96.9%)
20" wide = 1680 x 1050 = .258 pixel pitch (87.7%)
22" wide = 1680 x 1050 = .282 pixel pitch (95.9%)
24" wide = 1920 x 1200 = .270 pixel pitch (91.8%)
That same list in order of pixel pitch is:
20" wide = 1680 x 1050 = .258 pixel pitch (87.7%)
24" wide = 1920 x 1200 = .270 pixel pitch (91.8%)
22" wide = 1680 x 1050 = .282 pixel pitch (95.9%)
19" wide = 1440 x 900 = .285 pixel pitch (96.9%)
19" 4:3 = 1280 x 1024 = .294 pixel pitch (100%)
Note that the 24" wide is exactly half-way between the 20" wide and the 22" wide (and that the 20" wide and 22" wide have the same resolutions as each other – same real estate).