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":
Father: George Arnott AITKEN
(14 Feb 1869 New York, USA - 26 Feb 1931 Essex, New Jersey, USA)
Mother: Etola LOOMIS
(17 Jun 1872 Illinois, USA - 13 Jan 1931 Orange, Essex, New Jersey, USA)
Donald Guthrie AITKEN
(25 Nov 1906 East Orange, Essex, New Jersey, USA - 3 Oct 1975 Garden City, Nassau, New York, USA)
Dorothea M LANGE
(8 Jul 1908 New York, USA - 6 Sep 1987 Garden City, Nassau, New York, USA)
1906 - 1975 (68 years)
Ronald Coulter DAVIES 
(24 Dec 1937 Brooklyn, Kings, New York, USA - 12 Jul 2009 St James, Suffolk, New York, USA)