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":
    Pain de Chaworth (of Kempsford, Gloucestershire, England - Bef 11 May 1237)
       └─Patrick de Chaworth (Bef 1216 of Kempsford, Gloucestershire, England - Bef 23 Sep 1258)
        Hawise de London (Abt 1212 - Bef 23 Sep 1274)(m. Bef 19 Dec 1243)
           ├─Eve de Chaworth (1252 - Bef 14 Jun 1300) =>
           │ + Robert de Tibetot (1228 of Nettlestead, Bosmere, Suffolk, England -            │ 22 May 1298 Nettlestead, Bosmere, Suffolk, England)(m. Bef 18 Oct 1269)
           └─Patrick de Chaworth (Abt 1254 of Kidwelly, Carmarthenshire, Wales - Bef 7 Jul 1283) =>
            + Isabel de Beauchamp ( - Bef 30 May 1306)