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":
Lizzie Anne Cockburn DAVIDSON
(8 Apr 1882 Old Machar, Aberdeenshire, Scotland - 25 Dec 1953 Jarrahdale, Western Australia, Australia)
John BISHOP
(16 Feb 1879 Jarrahdale, Western Australia, Australia - 1956 Perth, Western Australia, Australia)
└─Arol BISHOP
(Mundijong, Western Australia, Australia;11 Nov 1910 - 7 Sep 1998)
Dorothy Edith MATHEWS
(3 Feb 1915 Keysbrook, Western Australia, Australia - 5 May 1995 Mandurah, Western Australia, Australia)
1882 - 1953 (71 years)
John BISHOP 
(16 Feb 1879 Jarrahdale, Western Australia, Australia - 1956 Perth, Western Australia, Australia)