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":
Blanche BOWLEY
(7 Sep 1872 Ashton Keynes, Wiltshire, England - 16 Jan 1942 Cirencester, Gloucestershire, England)
William George LOCK (30 Jan 1864 Tetbury, Gloucestershire, England - 22 Feb 1943 Cirencester, Gloucestershire, England)
└─William George LOCK (Cirencester, Gloucestershire, England;25 May 1894 - 25 Dec 1982)
Dorothy May COSSLETT (12 Jul 1894 Cardiff, Glamorgan, Wales - 29 Mar 1984 Cirencester, Gloucestershire, England)
└─William Owen LOCK (8 Aug 1927 Cirencester, Gloucestershire, England - 19 Mar 2010 Challex, Ain, Rhône-Alpes, France)
Eleanor JAMES (Long Ashton, Somerset, England;30 May 1933 - 2018)
(m. Jul 1952 Bristol, Gloucestershire, England)
1872 - 1942 (69 years)
William George LOCK 
(30 Jan 1864 Tetbury, Gloucestershire, England -