Yes I'm officially a newbie here but please don't hold that against me. I would have put this in the correct forum section if I could but I have a restricted account
Most of the good calculators do take the difficulty rating into account. In particular I like the one at bitcoinwisdom.com, it correctly puts in a default based on recent history, showing a 30% compounded increase.
At a 30% difficulty increase rate that means the 2016 blocks are being completed much faster. But it still assumes 14 weeks, with a parameter of 10-minute average block completion time, in units of 600 seconds. This is incorrect, and at a 30% difficulty increase rate it is quite significant. A 30% difficulty increase implies a 30% average reduction in the time to complete the 2016 blocks. It should instead be 420 seconds per block (70% of the baseline 600 seconds). (Actually this isn't quite true, but 420 serves to make the point, the true function is compounded over the 2016 iterations and resulting curve is slightly better for mining results, so 450 may be a better compound average number to use).
Try this in your favorite bitcoin calculator, you will see the estimates go down by more than half over the life of your rig.
My favorite calculator does at least have a field for block generation speed, but it should instead have a field for
base block generation speed (don't hard wire it so the calculator can support other virtual currencies), and separately the
effective block generation speed should be a calculated field:
effective block generation speed =
base block generation speed * (1 -
difficulty rate increase)
In the age of massive difficulty rate increases I think many are being lead astray and overestimating their potential earnings.
