I know this isn't the best way to do it, but after a quick shot at those age comparisons, I saw that it wasn't easy coming up with current character ages. So I this shows the character ages based on their original birthdays, actor ages, and the difference between those ages. I figure we can assume that the character ages should be somewhere close to their actor ages, except sometimes in the older folks. Many of them look way younger than their numeric value of their age! This is just a sampling of the characters... and the ones I could actually find birth dates for. Thanks to Jason47's website and Wikipedia for the info!
Character; Character Original Age; Actor Age Difference
Brady should be 22; Eric Martsolf is 43; the difference in age is 21 years
EJ should be 17; James Scott is 35; the age difference is 18 years
Hope should be 40; Kristian Alfonso is 51; the age difference is 11 years
JJ should be 10; Casey Moss is 21; the age difference is 11 years
Eric should be 30; Greg Vaughan is 41; the age difference is 11 years
Will should be 19; Guy Wilson is 29; the age difference is 10 years
Jennifer should be 38; Melissa Reeves is 47; the age difference is 9 years
Marlena should be 58; Deidre Hall is 67; the age difference is 9 years
Sami should be 30; Alison Sweeney is 38; the age difference is 8 years
Abe should be 61; James Reynolds is 68; the age difference is 7 years
Roman should be 64; Josh Taylor is 71; the age difference is 7 years
Theresa should be 24; Jen Lilley is 30; the age difference is 6 years
Chad should be 24; Billy Flynn is 29; the age difference is 5 years
Lucas should be 39; Bryan Dattilo is 43; the age difference is 4 years
Ciara should be 7; Lauren Boles is 10; the age difference is 3 years
Ari should be 1; the twins playing her are 2; the age difference is 1 year (actually, just a few months)
Theo should be 11; Terrell Ransom, Jr. is 11; no age difference
Kristen should be in her 40's; Eileen Davidson is 55; 10-15 age difference
John should be in his 60's; Drake Hogestyn is 61; no real age difference
Rafe should be in his 30's; Galen Gering is 43; 10+ age difference
I thought it was interesting that the younger the character, the closer in age their corresponding actor seems to be. I included some contemporaries with no character birth dates just for comparison's sake. While it is funny to see that EJ is supposed to be younger than Will, it is also interesting that Sami is supposed to be just 11 years older than Will! And Lucas is 9 years older than Sami. And Brady... he definitely takes the SORAS cake! If there's anybody else you'd like to see included here, let me know, and I'll have excel calculate their ages as well! Hope you found this as interesting as I did.
(Sorry for the poor chart... I couldn't find a nice way to insert one, so I had to manually space between columns.)
Edited to add: Well, that chart didn't take either! Sorry... I'm just leaving it as it. I'm sorry it isn't very easy to look at. The bottom three ages are actor ages, as I could not find any character birth dates for Kristen, John, or Rafe.
edited to make the list of characters, actors and ages easier to understand...JS