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":
James Ernest KIRKMAN
(4 Jun 1881 North Willoughby, New South Wales, Australia - 26 Jul 1957 Kellerberrin, Western Australia, Australia)
Matilda May MARTIN (1 Aug 1883 York, Western Australia, Australia - 29 Nov 1972 Mount Lawley, Western Australia, Australia)
└─Jesse Evelyn KIRKHAM (13 Jun 1910 Northam, Western Australia, Australia - 7 Oct 2005 Mount Lawley, Western Australia, Australia)
Ernest ADSHEAD (22 Jun 1902 Stockport, Cheshire, England - 20 Apr 2002 Mount Lawley, Western Australia, Australia)(m. 1933 Perth, Western Australia, Australia)
└─Anne V. ADSHEAD (5 Aug 1933 - 17 Jun 2020 Murdoch, Western Australia, Australia)
Joseph Murray NEWMAN (3 Dec 1929 Northam, Western Australia, Australia - 9 Feb 1981 Shoalwater, Western Australia, Australia)(m. 1952 Northam, Western Australia, Australia)
1881 - 1957 (76 years)
Matilda May MARTIN 
(1 Aug 1883 York, Western Australia, Australia -