I would like to see real-time mining profitability. The bitinfocharts web only shows day average. Is it possible to see how many hashes were actually needed to mine most recent Bitcoin block?
You cannot know how many hashes were actually performed for every block, because non-winning hashes aren't published.
There is however a simple formula to compute the expected number of hashes a block needs. Across many blocks of the same difficulty, that expected number is the average of the number of hashes per block.
The formula is almost exactly: 4295032833 times the difficulty.
This derives from the definition of difficulty: it is the ratio between the target hashes need to beat at difficulty 1 (0xffff0000000000000000000000000000000000000000000000000000 = 65535 ⋅ 2208), and the current target. The ratio between 2256 (the number of possible hashes) and that difficulty 1 target is 248 / 65535, which is 4295032833.000015259...