Civilization – How is attack strength calculated

The patch released on 15 December 2010 change some values, the values for non-standard map sizes are not updated

The mouseover for your own score helpfully shows from which categories how much of your score originates.

I've experimented a bit and my preliminary composition of the score is the following:

             Score
             Duel    Tiny    Small    Standard  Large
City         21      13      11       10        6
Population   6       4       3.5      4         ~1.5
Land         2.11    1.35    1.15     1               (water tiles don't count, the city hex does)
Technology   4       4       4        4         4
Wonder       40      40      40       25        40
Future Tech  ?       ?       ?        ?         ?

These results are from the start of a game, I assume they don't change but I can't be sure yet. It seems some things count for fractions of a point, so the numbers here may be rounded. The numbers also seem to be always rounded down, not to the nearest number.

Units and Gold do not seem to have any effect on the score.

Wonders count for a lot at 40 point per wonder. But also new cities (at standard map size) result in 19 points (10 for the city, 3 for 1 population and 6 for the land). Technology seems to be rated pretty low at 4 points, you have to research 5 technologies to get more points than one new city.

It's the percentage of the total technologies you've researched, as long as you have writing, otherwise it's always 0. Note that what follows is not my research, I found this on the CivFanatics forums:

From Assets/UI/InGame/Popups/Demographics.lua:

function GetLiteracyValue( iPlayer )

    local pTeamTechs = Teams[ Players[ iPlayer ]:GetTeam() ]:GetTeamTechs();

    local iWriting = GameInfoTypes[ "TECH_WRITING" ];
    if( iWriting ~= nil and 
        not pTeamTechs:HasTech( iWriting ) ) then
        return 0;
    end

    local iCount = 0;
    for row in GameInfo.Technologies() do
        if( pTeamTechs:HasTech( row.ID ) ) then
            iCount = iCount + 1;
        end
    end

    return 100 * iCount / #GameInfo.Technologies;
end

Since "Future Tech" never gets fully researched, you can never reach 100% literacy.