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":
Eleanor SEDGWICK
(22 Jul 1879 England - 5 Sep 1941 White Gum Valley, Western Australia, Australia)
James JEFFERY
(16 Sep 1877 Spring Grove, New South Wales, Australia - 2 Mar 1956 North Perth, Western Australia, Australia)
└─Victor John JEFFERY
(1909 White Gum Valley, Western Australia, Australia - 1982 Western Australia, Australia)
Emmalene May BELL
(1909 Fremantle, Western Australia, Australia - 1986 Western Australia, Australia)
└─Lynn JEFFERY
(29 Oct 1939 - 21 Nov 2020 Baldivis, Western Australia, Australia)
1879 - 1941 (62 years)
James JEFFERY 
(16 Sep 1877 Spring Grove, New South Wales, Australia - 2 Mar 1956 North Perth, Western Australia, Australia)