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":
Cecil James RYAN
(1905 Panmure, Victoria, Australia - 22 Aug 1974 Warrnambool, Victoria, Australia)
Mavis Elvie SHEPPARD
(Warrnambool, Victoria, Australia;25 Mar 1913 - 5 Nov 1977)(m. 1929 Victoria, Australia)
└─Beverley Fay RYAN
(22 Feb 1942 Warrnambool, Victoria, Australia - 15 Feb 2020 Bairnsdale, Victoria, Australia)
Geoffrey John WHYKES
(11 Feb 1933 - 24 Jul 1998 Bairnsdale, Victoria, Australia)
1905 - 1974 (69 years)
Mavis Elvie SHEPPARD 
(Warrnambool, Victoria, Australia;25 Mar 1913 - 5 Nov 1977)(m. 1929 Victoria, Australia)