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":
Catherine W. UNKNOWN (1865 - 1 Jan 1950 Mount Lawley, Western Australia, Australia)
└─Harold Leonard DIGBY (Abt 1890 - 20 Dec 1966 Fremantle, Western Australia, Australia)
Nelmore Alice DOUST (1894 Bridgetown, Western Australia, Australia - 11 Oct 1988 Como, Western Australia, Australia)(m. 1919 Bridgetown, Western Australia, Australia)
│ + Joan M. NICHOLSON (1918 - 3 Aug 1998 Maylands, Western Australia, Australia)
└─Nelmore June DIGBY (28 Jul 1922 Kellerberrin, Western Australia, Australia - 13 Jun 1977 Shoalwater Bay, Western Australia, Australia)
James Reed INGRAM (8 Apr 1902 Marshall, Missouri, USA - 8 Mar 1991 bur.Albany, Western Australia, Australia)(m. 8 Mar 1947 Sydney, New South Wales, Australia)
1861 - 1944 (83 years)
Nelmore Alice DOUST 
(1894 Bridgetown, Western Australia, Australia -