dBi and dBd

All too often the calculated value that you have is not in the right scale that
is required for the form or questioner. Therefore, it is necessary to convert
from either dBi to dBd or from dBd to dBi.
To convert a value in dBi to the equivalent dBd value, the following equation
is utilized:
dBd
dBi  2.14
Therefore,Table 11-3 can be used to help reinforce the conversion process
that shows the calculated values along with the nearest approximate value
found.
To convert a value in dBd to the equivalent dBi value, the following equation
is utilized:
dBi
2.14  dBd
Therefore,Table 11-4 can be used to help reinforce the conversion process
that shows the calculated values along with the nearest approximate value
found.
446 Chapter 11
dBi dBd
5 2.86 (3dBd)
10 7.86 (8dBd)
12 9.86 (10dBd)
14 11.86 (12dBd)
18 15.86 (16dBd)
21 18.86 (19dBd)

dBd dBi
3 5.14
10 12.14
12 14.14
14 16.14
18 20.14
21 23.14