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: Joseph MIDGLEY
(Keighley, Yorkshire, England;27 Nov 1670 - 6 Jun 1738)
Mother: Mary HOLMES
(Keighley, Yorkshire, England;14 Dec 1676 - 8 Jun 1741)
Agnes MIDGLEY
(27 Dec 1702 Keighley, Yorkshire, England - DECEASED)
Thomas MOORHOUSE
(Bef 21 Oct 1714 Keighley, Yorkshire, England - DECEASED)
└─John MOORHOUSE
(15 Jun 1735 Embsay, Yorkshire, England - Aug 1825 Storiths, Yorkshire, England)
Isabella PLACE
(1743 Grassington, Yorkshire, England - Jan 1828 Storiths, Yorkshire, England)
└─Robert MOORHOUSE
(Grassington, Yorkshire, England;1765 - 17 Jun 1822)
Isabel CONSTANTINE
(13 Dec 1767 Conistone, Yorkshire, England - 1 May 1808 Grassington, Yorkshire, England)
└─John MOORHOUSE
(1793 Grassington, Yorkshire, England - Bef 1841)
Sarah WHITAKER
(Abt 1796 Thorp, Yorkshire, England - May 1864 Grassington, Yorkshire, England)
1702 - DECEASED
Isabel CONSTANTINE 
(13 Dec 1767 Conistone, Yorkshire, England - 1 May 1808 Grassington, Yorkshire, England)