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: Albert Henry GREGORY
(2 Apr 1886 Prahran, Victoria, Australia - DECEASED)
Mother: Florence May ARESEM
(Willagee, Western Australia, Australia;19 Aug 1890 - 2 Sep 1962)
Alfred Henry GREGORY
(1913 Fitzroy, Victoria, Australia - 23 Aug 1971 Fremantle, Western Australia, Australia)
Sarah MILLAN
(8 Feb 1914 Fremantle, Western Australia, Australia - 27 Jul 1998 Shoalwater, Western Australia, Australia)(m. 13 May 1933 Fremantle, Western Australia, Australia)
├─Graeme GREGORY
( - 13 Dec 2008 Coolup, Western Australia, Australia)
└─Sandra Maxine GREGORY
(Abt 1947 - 10 Oct 1969 Safety Bay, Western Australia, Australia)
1913 - 1971 (58 years)
Sarah MILLAN 
(8 Feb 1914 Fremantle, Western Australia, Australia -