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":
Reuben TAYLOR
(Abt 1890 - 27 Feb 1969 South Perth, Western Australia, Australia)
Rose Alice COOPER (29 Jan 1891 Toodyay, Western Australia, Australia - 24 Oct 1970 South Perth, Western Australia, Australia)(m. 1912 Perth, Western Australia, Australia)
└─Harold TAYLOR (14 Apr 1921 Perth, Western Australia, Australia - 15 Aug 1999 Bunbury, Western Australia, Australia)
Doreen May PARSONS (21 May 1922 Geraldton, Western Australia, Australia - 29 Nov 1986 Langford, Western Australia, Australia)(m. 1942 Geraldton, Western Australia, Australia)
Abt 1890 - 1969 (~ 79 years)
Rose Alice COOPER 
(29 Jan 1891 Toodyay, Western Australia, Australia -