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":
Richard FUTTER
(Horsham St Faith, Norfolk, England;Abt 1685 - Jul 1771)
Elizabeth DANIELL
(Horsham St Faith, Norfolk, England;Abt 1685 - Abt May 1771)
(m. 22 Aug 1713 Norwich, Norfolk, England)
└─James FUTTER
(Horsham St Faith, Norfolk, England;5 Dec 1714 - 27 Jan 1779)
Rose GRICE
(1709 Mattishall Burgh, Norfolk, England - 1803)
└─Rose FUTTER
(1743 Horsham St Faith, Norfolk, England - DECEASED)
Samuel BROOM
(Abt 1724 Norfolk, England - Apr 1793 Horsham St Faith, Norfolk, England)
Abt 1685 - 1771 (~ 86 years)
Elizabeth DANIELL 
(Horsham St Faith, Norfolk, England;Abt 1685 - Abt May 1771)