I have a 225v main panel and I want to run a sub panel for 13 30amp breakers what size sub panel should I get its for lights that draw 7.5 amps and have 1000w bulbs

You're not suing 30A breakers for that lighting, are you?? That is a no-no.



its for lights that draw 7.5 amps and have 1000w bulbsHow many?

There are going to on 3 lights each breaker

40 lights in the room each ballast draws 7.5amps with 1000w bulbs

FORTY 1000w lights in one room?? Must be one hell of a room!

Is this at 120v? Where are you getting 7.5A from.
1000 watts at 120v is 8.33a not taking into account ballast draws if these are HID lights.

What are you lighting if I may ask?
Is this in a residence?
Is this in the US?

If this is a residence in the US you CANNOT use 30A circuits.

This whole thing is very vague. You are leaving out many important details.

It's a commercial building with a 800amp switch gear with a 112kv transformer and I want to run a sub panel for lights in a room that draw(ballasts) 7.5 amps and have 1000w bulbs total of 39 lights the lights are 220v what size sub panel can I put in the room

800A at what voltage?
Is the 112kVA trans 120/240v secondary? (there is NO such thing as "220v" any more)
Will the panel be wired from the transformer?

See what I am getting at? WAY too many unknowns.

PLEASE hire an electrician.