Ultimate net value worked out (8)
I believe the answer is:
eventual
'ultimate' is the definition.
('eventual' can be similar in meaning to 'ultimate')
'net value worked out' is the wordplay.
'worked out' indicates an anagram.
'net'+'value'='netvalue'
'netvalue' anagrammed gives 'EVENTUAL'.
(Other definitions for eventual that I've seen before include "coming after some time" , "Happening in due course" , "Ultimately resulting" , "Coming at last, ultimate" , "Occurring at the end, ultimate" .)