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":
Violet May ROBERTSON
(20 May 1897 Townsville, Queensland, Australia - 28 Jan 1957 Manjimup, Western Australia, Australia)
Francis William Hughes ROBBINS (25 Aug 1899 Eddington, Victoria, Australia - 1968 Kalgoorlie, Western Australia, Australia)(m. 12 May 1923 Swan, Western Australia, Australia)
└─Ronald ROBBINS (22 Jul 1926 Coolgardie, Western Australia, Australia - 21 Sep 1995 Fremantle, Western Australia, Australia)
Irene Jessie MEREDITH (1915 Northam, Western Australia, Australia - 8 Aug 1992 Victoria Park, Western Australia, Australia)(m. 1960 East Coolgardie, Western Australia, Australia)
1897 - 1957 (59 years)
Francis William Hughes ROBBINS 
(25 Aug 1899 Eddington, Victoria, Australia -