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":
George Henry SMITH
(21 Jun 1881 Naracoorte, South Australia, Australia - 10 May 1949 South Australia, Australia)
Isabella Maria CAIRNS (31 Jul 1888 Cape Town, Western Cape, South Africa - 30 Dec 1967 Adelaide, South Australia, Australia)(m. 19 Oct 1907 South Africa)
└─Robina Isabella SMITH (4 Nov 1916 Alberton, South Australia, Australia - 8 Jan 1991 Brisbane, Queensland, Australia)
James Douglas RICHARDS (21 Feb 1913 Hindmarsh, South Australia, Australia - : 19 Jul 1980 Adelaide, South Australia, Australia)
1881 - 1949 (67 years)
Isabella Maria CAIRNS 
(31 Jul 1888 Cape Town, Western Cape, South Africa -