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":
Agnes HAY
(Abt 1883 - 16 Jun 1963 Rivervale, Western Australia, Australia)
Robert Alexander WILLIS (Abt 1883 - 24 Oct 1961 Rivervale, Western Australia, Australia)
(m. 1910 Black Range, Western Australia, Australia)
   └─James George WILLIS (7 Nov 1922 Palmyra, Western Australia, Australia -     4 Dec 2007 Stirling, Western Australia, Australia)
    Marguerite Norma Joyce GIBSON (21 Aug 1923 Bunbury, Western Australia, Australia -     19 Oct 2009 Innaloo, Western Australia, Australia)(m. 1949 Perth, Western Australia, Australia)