Is there any chart or webpage to help me figure it out if its good mining upon certain conditions?

For example: If my electricity cost is 15c (kw/hr) , and I cant get 6 x rx 580 vega (cpu + supply power, etc)  at $3.000 usd . How long does it take to get investment back.

Looking for a chart where I can play with numbers to see minimun electricity cost, etc .

Thanks