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: Peter WILLOUGHBY (12 Nov 1809 St. Agnes, Cornwall, England - 9 Jun 1878 Skinner's Bottom, Cornwall, England)
Mother: Kezia NICHOLAS (10 Nov 1814 St. Agnes, Cornwall, England - 14 Oct 1884 Skinner's Bottom, Cornwall, England)
Edward WILLOUGHBY
(1836 St. Agnes, Cornwall, England - 27 May 1910 Montana, USA)
Elizabeth Ann POOLEY (Jan 1839 St. Agnes, Cornwall, England - DECEASED)(m. Abt 1859)
   └─Richard WILLOUGHBY (1876 St. Agnes, Cornwall, England - 13 Jan 1956 Butte, Silver Bow, Montana, USA)
    + Rose TEUSHER (Abt 1868 Switzerland - DECEASED)(m. 28 Nov 1941 Whitehall, Jefferson, Montana, USA)