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":
Father: William HILL
(1 Oct 1832 Essex, England - 3 Jun 1921 Gingin, Western Australia, Australia)
Mother: Sarah Ann DOHERTY
(1837 Ireland - 3 Feb 1894 Gingin, Western Australia, Australia)
William Thomas HILL
(27 Jul 1872 Gingin, Western Australia, Australia - 6 Sep 1956)
Elizabeth LARWOOD
(4 Jul 1862 Moore River, Western Australia, Australia - 19 Aug 1939 Gingin, Western Australia, Australia)
└─Clayton Thomas HILL
(26 Mar 1903 Gingin, Western Australia, Australia - 30 May 1958)
1872 - 1956 (84 years)
Elizabeth LARWOOD 
(4 Jul 1862 Moore River, Western Australia, Australia - 19 Aug 1939 Gingin, Western Australia, Australia)