Border growth vs Civics progress

[smvalentine]

I know Culture contributes to both border growth and progress toward the current civic.
I believe only Culture generated by each city contributes to border growth, while civic progress is civilization wide.

What I'm not clear on is whether culture contributes to both, or if one subtracts from the other.
(Similar to food being eaten by citizens and only surplus food contributing to population growth.)
Is some portion of the culture generated by a city consumed by border growth and only "excess culture" going toward civics?

 

[S1AL]

Each city's individual culture determines border growth rate.

 

[Browd]

But it does not subtract from empire-wide culture.

 

[sa1vy]

Border growth has its own counter in each individual city, just like population growth. If you have +4 food surplus every term, and the threshold for a new citizen being born is at 60 food, then it takes 60/4 = 15 turns to grow.
Likewise, if the city is making 7 culture per turn (including great works! put them in cities you want to expand!), and the threshold to expand the borders is 100 culture, then it'll take 15 turns. It doesn't factor in civic progression or your empire's culture at all.
For both these measures, the threshold increases every time. It can get exceedingly slow after a while. Border growth if so ridiculously slow...

 

[Infixo]

Border growth if so ridiculously slow...

Imho, this is a design choice from Firaxis, one of the fundamental ones, to make terrain more valuable and whatever you put on that terrain - be it a district, or wonder, or an improvement - to be more important.