any one know how to do the math on , at what price does btc have to drop to ,to have 0.00 divdends. a rough estimate will work too.
Your question doesn't make sense. Dividends are not a function of BTC price.
You probably are asking what difficulty. I don't know, but you can probably figure that double the difficulty is 1/2 the dividend. So if the dividend is ~1000 satoshis would be less ~ 0 after 11 doublings. So 140 PH/s * 2048 ==> ~ 280 EH/s. (1000 PH/s = 1 EH/s)