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: Rennie Watt MILLEN
(4 Jun 1859 Dalry, Ayrshire, Scotland - 21 Nov 1926)
Mother: Emily Cecilia O'BRIEN
(4 Sep 1861 Creswick, Victoria, Australia - 19 Aug 1939)
Christopher Coppin MILLEN
(20 Mar 1890 Broken Hill, New South Wales, Australia - 22 Apr 1935 Perth, Western Australia, Australia)
Unice Evelyn JAMES
(20 Feb 1893 Parramatta, New South Wales, Australia - 24 Mar 1964 Western Australia, Australia)
1890 - 1935 (45 years)
Unice Evelyn JAMES 
(20 Feb 1893 Parramatta, New South Wales, Australia - 24 Mar 1964 Western Australia, Australia)