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":
William Robert PAGE
(1871 Boroondara, Victoria, Australia - 4 Dec 1927 Boyanup, Western Australia, Australia)
Amy Isabella ECCLESTONE (1882 Boyanup, Western Australia, Australia - 22 Aug 1942 Wellington, Western Australia, Australia)
│ + Rebecca Rose FLEMMING (1901 York, Western Australia, Australia - │ 10 Aug 1991 Kwinana, Western Australia, Australia)(m. 1929 Perth, Western Australia, Australia)
└─Edna Amy Crystal PAGE (Bunbury, Western Australia, Australia;29 Dec 1919 - 21 Dec 2015)
Laurence James Absolom BICKLEY (Bunbury, Western Australia, Australia;14 Aug 1917 - 14 Sep 1983)
(m. 1942 Swan, Western Australia, Australia)
1871 - 1927 (56 years)
Amy Isabella ECCLESTONE 
(1882 Boyanup, Western Australia, Australia -