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":
William FOX
(3 Nov 1819 St. Hilary, Cornwall, England - 28 Nov 1859 Linden, Iowa, Wisconsin, USA)
Ann BUCKETT
(5 Feb 1820 Perranuthnoe, Cornwall, England - 30 Mar 1902 Linden, Iowa, Wisconsin, USA)
(m. 30 Nov 1844 Perranuthnoe, Cornwall, England)
└─Joseph Henry FOX
(17 May 1857 Mineral Point, Iowa, Wisconsin, USA - 8 Sep 1928 Alexandria, Hanson, South Dakota, USA)
Edith Eugenia REYNOLDS
(7 Mar 1863 Mineral Point, Iowa, Wisconsin, USA - 5 Nov 1941 Alexandria, Hanson, South Dakota, USA)
└─Bert Allen FOX
(14 Mar 1895 Alexandria, Hanson, South Dakota, USA - 28 Apr 1971 At Sea)
Nina May EGGLESTON
(21 Feb 1902 Tilden, Cherokee, Iowa, USA - 5 Aug 2000 Reno, Washoe, Nevada, USA)
1819 - 1859 (40 years)
Ann BUCKETT 
(5 Feb 1820 Perranuthnoe, Cornwall, England - 30 Mar 1902 Linden, Iowa, Wisconsin, USA)