The paper length is not relevant since the chart flows from one page to the next.
Mobile
in.
mm
Portrait
2.75
70
For smart phones, not for printing
Landscape
5.5
140
For smart phones, not for printing
USA & Canada
in.
mm
Letter Portrait
8.5
216
Also Legal Portrait
Letter Landscape
11
279
Legal Landscape
14
356
Also Ledger Portrait
Ledger Landscape
17
432
International
in.
mm
A5 Portrait
5.82
148
A4 Portrait
8.25
210
Also A5 Landscape
A4 Landscape
11.71
297
Also A3 Landscape
A3 Landscape
16.54
420
The Text+ programs assume that the right and left margins are each about 25mm (1/2 inch) wide.
On the Format for Printing page, differences in page margins can be accommodated by the "fudge factor":
Nora Elizabeth BLACK (10 Sep 1857 West Alexander, Washington, Pennsylvania, USA - 27 Nov 1932 Picher, Ottowa, Oklahoma, USA)
└─Nora Mary PATTON (17 Feb 1888 Neosho, Kansas, USA - 9 Jan 1961 Pittsburg, Crawford, Kansas, USA)
William Ottis GUINN (28 Dec 1876 Warren, Indiana, USA - 26 Dec 1961 Pittsburg, Crawford, Kansas, USA)
(m. 1 Oct 1905 Webb City, Jasper, Missouri, USA)
└─Arthur Ray GUINN (28 May 1908 Pittsburg, Crawford, Kansas, USA - 25 Jun 1985 Tulsa, Tulsa, Oklahoma, USA)
Kathryn Edith AYRES (29 Nov 1915 Custer City, Custer, Oklahoma, USA - 17 Oct 1991 Tulsa, Tulsa, Oklahoma, USA)(m. 3 Oct 1936 Okmulgee, Okmulgee, Oklahoma, USA)
1856 - 1928 (71 years)
Nora Elizabeth BLACK 
(10 Sep 1857 West Alexander, Washington, Pennsylvania, USA -