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":
Sarah KELLY
(26 Feb 1887 Cropping, South Australia, Australia - 19 Oct 1936 Nedlands, Western Australia, Australia)
Thaddeus HOWELL (7 Mar 1882 Carlton, Victoria, Australia - 28 Jun 1969 Perth, Western Australia, Australia)
├─Irene HOWELL (Perth, Western Australia, Australia;31 Jul 1916 - 10 Jun 1954)
│ + George Borthwick THORBURN (1902 Girvan, Ayrshire, Scotland - │ 13 Jul 1988 Inglewood, Western Australia, Australia)(m. 1941 Perth, Western Australia, Australia)
└─Ronald George HOWELL (Perth, Western Australia, Australia;19 Jun 1927 - 5 Sep 2016)
Marion Elsie PERRY (1 Oct 1927 Perth, Western Australia, Australia - 17 Nov 2015 Joondalup, Western Australia, Australia)(m. 10 Mar 1951 Perth, Western Australia, Australia)
1887 - 1936 (49 years)
Thaddeus HOWELL 
(7 Mar 1882 Carlton, Victoria, Australia - 28 Jun 1969 Perth, Western Australia, Australia)