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: Robert HALL
(North Shields, Northumberland, England;Abt 1855 - 1934)
Mother: Mary Jane ENGLISH
(Abt 1859 North Shields, Northumberland, England - DECEASED)
William Gray HALL
(26 Jun 1901 Tynemouth, Northumberland, England - 1970 Fremantle, Western Australia, Australia)
Dora PEARSON
(20 Apr 1901 Tynemouth, Northumberland, England - 13 Apr 1982 Fremantle, Western Australia, Australia)(m. 15 Jun 1929 Perth, Western Australia, Australia)
William Henry DYMOND
(3 Jun 1927 Fremantle, Western Australia, Australia - 22 Jun 2008 Geraldton, Western Australia, Australia)(m. 1951 Fremantle, Western Australia, Australia)
1901 - 1970 (68 years)
Dora PEARSON 
(20 Apr 1901 Tynemouth, Northumberland, England -