This is the first year when it's being broadcast by 2 broadcasters.
The best viewing figures since 2008

18+ age group, the whole country (add 1-2% for all age groups for STB and 0.2% for UA
BC):
Semi #1
STB = 9.7%
UA
BC = 2.3% *
Semi #2
STB = 16%
UA
BC = 4% *
The final
STB = 18.9%
UA
BC = 6.3%
* no data for UA
BC semis so I used my estimations.
Approx. in total (all age groups):
Webcast:
STB = no data
UA
BC = 200 000 (the site + YT from the commentators room)
Here's the history of our ESC finals ratings until 2018:
18+ (the whole country) is the purple one.
2014 - the war with Russia started
2015 - we didn't participate but there was a broadcast
Google trends (1 week):
A person - #1 Melovin
An event - #1 Eurovision 2018
18+ age group, the whole country (add 1-2% for all age groups for STB and 0.2% for UA
Semi #1
STB = 9.7%
UA
Semi #2
STB = 16%
UA
The final
STB = 18.9%
UA
* no data for UA
Approx. in total (all age groups):
S1 = 13.2%
S2 = 21.7%
The final = 27.2%
S2 = 21.7%
The final = 27.2%
Webcast:
STB = no data
UA
Here's the history of our ESC finals ratings until 2018:

18+ (the whole country) is the purple one.
2014 - the war with Russia started
2015 - we didn't participate but there was a broadcast
Google trends (1 week):
A person - #1 Melovin
An event - #1 Eurovision 2018