I can't find this info anywhere and all they give me is the ratio. However, I need the exact/approximate values
In general, you can get good general dimensions from the Airplane Characteristics for Airport Planning documents (Boeing). These documents include the overall dimensions and everything relevant for the airport. This does not include the chord length though.
To get more accurate dimensions, you can download CAD drawings from Boeing. I did this for the 747-400 and the 747-8I and measured the chord length in three places along the wing:
As you can see, the chord length varies between 14.84m at the root and 3.70m at the tip (before the winglet). The wing for the 747-8 has been slightly re-designed:
While keeping its basic structure and sweep, the wing is thicker and deeper, holding more fuel, and wider with raked wingtips.
The differences in chord length are rather small (possibly less than the accuracy of these drawings):
I estimate a 565 or 567" chord length where the wing meets the fuselage and wing-to-body (WTB) fairing, based on the Fuselage Station Diagram from the Structural Repair Manual: https://static.rcgroups.net/forums/attachments/1/8/4/2/1/0/a5165653-56-img063%20-%20Copy.jpg I would subtract 20" to account for the curvature at the leading edge where the WTB curves and smooths into the leading edge, unless you are going to accurately model that curve.
If you are making a model it'll be helpful to be aware of how the wing is constructed. The primary structure is the aluminum wingbox structure, which takes all the flight loads and spans from wingtip to wingtip, including the center wing section/tank (which is hidden inside the WTB and fuselage).
On a real Boeing this wingbox structure is usually a darker color (except on United Airlines and maybe Singapore and/or Thai and on 747-8s) because it is painted with corroguard.
The leading edge and trailing edge are attached to the wing box along with the flight controls, flaps and everything else.
Over 20 years ago I assembled 747-400 center wing sections and can tell you that a 6' person can stand up inside the first bay of the center wing tank (CWT). After TWA800 happened the media came through our work area and took pictures: Here is a photo showing a guy I worked with inside the CWT: https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse3.mm.bing.net%2Fth%3Fid%3DOIP.AOrngW4VMwMG65-dPj3dgwHaGo%26pid%3DApi&f=1
Here, you'll like this too: https://static.rcgroups.net/forums/attachments/1/8/4/2/1/0/a5165657-231-img067%20-%20Copy.jpg
Here is NASA's 747 with the wing removed clearly showing the wing box: https://s.hdnux.com/photos/27/13/50/6076974/3/1200x0.jpg
Here are all the photos at rcgroups.net , including more of the 747: https://www.rcgroups.com/forums/thumbgallery.php?do=threadgallery&t=1734624
Are you making a CAD model or a physical model? Is it a flying R/C model?
(I just signed up here with my google account to answer this question, so I'm not sure how I will be alerted of your reply, but I assume that I will be).
Matt in Seattle