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":
Sophia Elizabeth ADAMS
(Apr 1878 Leighton Buzzard, Bedfordshire, England - 9 Sep 1971 Nedlands, Western Australia, Australia)
William Lancaster STUMP
(1873 Islington, Middlesex, England - 13 Mar 1928 Merredin, Western Australia, Australia)
└─Winifred Ethel STUMP
(Apr 1897 West Ham, Essex, England - 30 Jun 1982 Nedlands, Western Australia, Australia)
Francis Henry KINGSTON
(Abt 1892 England - 22 Aug 1978 Nedlands, Western Australia, Australia)
└─Joyce KINGSTON
(Perth, Western Australia, Australia;1920 - 2009)
Arthur Stanley HARRIES
(13 Jun 1911 Blackpool, Lancashire, England - 2 Nov 2006 Perth, Western Australia, Australia)
1878 - 1971 (~ 93 years)
William Lancaster STUMP 
(1873 Islington, Middlesex, England - 13 Mar 1928 Merredin, Western Australia, Australia)