Calculating speaker wattage

[Augusts]

Hello, is there a formula by which you can calculate the loudspeaker wattage required when building a system? For example what kickbass wattage and db level should I choose If I have a 270w sub 95db/1m?

forexample a formula by which it would be possible to calculate 30hz-300w 95db sub and 120 hz- ?? - 98db kickbass

Thanks
A

 

[Bone]

No

 

[Augusts]

Would be cool though. input frequency, input sensitivity, get watts. I think its doable. excel sheet thingy