According to the Cyber Nations Information Index, the nation strength formula is: Land Purchased * 1.5 + Tanks Deployed * .75 + Tanks Defending * 1 + Cruise Missiles * 1.5 + Nuclear Purchased * 50 + Technology Purchased * 20 + Infrastructure Purchased * 3 + Actual Military * .10 + (aircraft rating totals * 5).
If I add all that up for my nation:
780.032 * 1.5 + 0 * .75 + 0 * 1 + 0 * 1.5 + 0 * 50 + 304.09 * 20 + 3469.74 * 3 + 12952 * .1 + 60 * 9 * 5 = 21,656.270
However, my actual nation strength is 21,071.250.
I thought the problem might be land purchased, as the alliance ranking page shows different values than my nation page (my nation page says 780.032 miles purchased, 260.743 from natural growth, the alliance rankings shows 587.26), but none of the three available land values add up to the correct strength. The value from natural growth comes closest, but it's still off by about 200, and that doesn't match the formula anyways.
So, long story short, the nation strength formula is wrong, or I'm really stupid. Which is it?