Formulas for calculating current target and difficulty

Question

I'm looking for formulas on how Monero/CryptoNight/Keccak1600 are calculating difficulty and current target.

E.g. something like:

max_target =?
current_target = f(max_target, blockrate) //some function f

I assume these are different from bitcoin/SHA256.

I'm not interested in mining profitability calculations per second, just in the basics of the PoW algorithms.

Answer 1

The specific difficulty target function can be found in the source code here.

Difficulty is adjusted so that a block is mined every 120 seconds on average. What affects this is the total network hashrate and the time it's taking to mine a block. If total network hashrate is high, difficulty is adjusted up. If total network hashrate is low, difficulty is adjusted down, so that a block is expected to be be mined in 120 seconds.