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":
John Dickinson (Bef 22 Aug 1624 chr.Billingborough, Lincolnshire, England - 19 May 1676 Turner's Fall, Franklin, Massachusetts)(m. Between 1647 and 1648)
   └─Mehitable Dickinson (1666 - 30 Jun 1735 bur.Amherst, Hampshire, Massachusetts)
    John Ingram (29 Jun 1661 - Aft Oct 1742 Amherst, Hampshire, Massachusetts)(m. 26 Jun 1689)
       └─Rebecca Ingram (5 Nov 1704 - 21 Jul 1789)
        Dr. Nathaniel Smith (16 Feb 1702 of Amherst, Hampshire, Massachusetts -         21 Jul 1789 Amherst, Hampshire, Massachusetts)(m. 11 Nov 1726)
           └─Dorothy Smith (23 Feb 1729 - 3 Jun 1756) =>