Block reward is a fixed amount , so it's a specific number you will get each block you hit , i think its something like 10 coins per block reward .

Only real way to get info would be to stake but since staking hasn't begun properly yet it's hard to get accurate numbers .

A semi accurate estimation would be to figure out how many BRX total will be staking , how big your stack sizes you choose , then figure out the 5% POS average for the year on BRK coins created .

I think if none of the BRX coins are sold in this IPO they will be held in bittrex cold storage not being staked (can dev's confirm for sure) so staking for the first few months + will be more than double when all coins are in circulation