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: Melburn MANN
(Tetbury, Gloucestershire, England;14 Mar 1826 - 20 Feb 1903)
Mother: Jane PLASTEE
(Charlton, Gloucestershire, England;1825 - 14 Nov 1893)
Phoebe Jane MANN
(1854 Tetbury, Gloucestershire, England - 1884 Taree, New South Wales, Australia)
Richard HARDY
(18 Jul 1845 Thalaba, New South Wales, Australia - 4 Aug 1929 Stony Creek, New South Wales, Australia)
└─Richard Allan HARDY
(11 Nov 1875 Cape Hawk, New South Wales, Australia - 26 Nov 1953 Taree, New South Wales, Australia)
Catherine HINTON
(Taree, New South Wales, Australia;24 Mar 1888 - 1 Nov 1970)
└─Neville HARDY
(Taree, New South Wales, Australia;24 Feb 1925 - 14 Nov 2014)
1854 - 1884 (30 years)
Richard HARDY 
(18 Jul 1845 Thalaba, New South Wales, Australia - 4 Aug 1929 Stony Creek, New South Wales, Australia)