What is the right algorithm to calculate estimated daily earning per mhs

lets talk about moon coin
http://www.coinwarz.com/cryptocurrency/coins/mooncoin

Block Reward   1m coin
Block Time           90 seconds
Exchange rate     0.00000001 btc
Diff                    26.17


someone told me that for usde

(24/(6.25*2^32/(1*10^6)/3600)*4000)*(5.5*10^-7) = 0.007081

6.25 = diff
4000 = blockreward
5.5*10^-7 = 55 satoshi
but not sure where to type the block time?