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":
Isabella Stewart GEORGE
(15 Sep 1889 Glenorchy, Queenstown-Lakes, Otago, New Zealand - 3 Jul 1955 Birchwood, Southland, Southland, New Zealand)
John Hastings WATSON
(12 Jul 1879 Cambrian, Central Otago, Otago, New Zealand - 15 Jan 1969 Riverton, Southland, Southland, New Zealand)
└─James George WATSON
(1912 New Zealand - 4 Jul 1996 Invercargill, Southland, New Zealand)
Ellen Louisa KOCH
(23 Apr 1919 Glenorchy, Queenstown-Lakes, Otago, New Zealand - 25 Jan 2001 Invercargill, Southland, New Zealand)
1889 - 1955 (65 years)
John Hastings WATSON 
(12 Jul 1879 Cambrian, Central Otago, Otago, New Zealand - 15 Jan 1969 Riverton, Southland, Southland, New Zealand)