Dish Size Chart

How to use Lyngsat to look up the dish size required for a satellite

First look up the satellites footprint coverage map found on Lyngsat.com, ensure that you have the correct beam – different countries may be served by the same satellite for example Hispasat serves South America & Portugal. Lastly read the expected signal strength where you are installing the dish

64 dBW 22 cm
63 dBW 24 cm
62 dBW 26 cm
61 dBW 28 cm
60 dBW 30 cm
59 dBW 32 cm
58 dBW 34 cm
57 dBW 36 cm
56 dBW 38 cm
55 dBW 40 cm
54 dBW 45 cm
53 dBW 50 cm
52 dBW 50 cm
51 dBW 55 cm
50 dBW 60 cm
49 dBW 60 cm
48 dBW 60 cm

47 dBW 75 cm
46 dBW 80 cm
45 dBW 90 cm
44 dBW 90 cm
43 dBW 100 cm
42 dBW 110 cm
41 dBW 120 cm
40 dBW 120 cm
39 dBW 135 cm
38 dBW 150 cm
37 dBW 180 cm
36 dBW 240 cm
35 dBW 300 cm
34 dBW 355 cm
33 dBW 400 cm
32 dBW 450 cm

Signal Strength EIRP Field Intensity dBwatt – Antenna diameter cm  

EIRP – Abbreviation for Effective-Isotropic-Radiated-Power
Effective Isotropic Radiated Power is the apparent power transmitted towards the receiver, if it is assumed that the signal is radiated equally in all directions, such as a spherical wave emanating from a point source; in other words, the arithmetic product of the power supplied to an antenna and its gain.

Abbreviations found on footprint maps:
EIRP = G * P = 10(g/10) * P [W]
G: Antenna gain coefficient
g: Antenna gain [dBi]
P: Power [W]
The table contains values for the Ku band. The values shown in the table assume having an Universal LNB with noise figure of 0.7 dB:

In the footprint above , the signal from Astra 1 is high and coverage in England will be very good and with uniform signal everywhere.

The  table assumes even coverage within the footprint, of course in practice the coverage is not even, you may find areas well down from estimated values. This applies more for satellites towards the  edge of our horizon, although most of the satellites within 20 degrees of due  south over the UK are fine, some  for  example in Manchester centre 2018 the Turksat signal 42 deg east , is only half  the value  indicated, so only use the table as a guide!

Hellas 3 satellite is just one example of where the signal gets progressively weaker from east to west, so some testing would be necessary . Always bear in mind the weather conditions when you install, if it is clear and the signal is only just ok, go bigger and create some safety margin or the picture make start to breakup in bad weather.