The location of the c.g. depends on the plane's configuration. Conventional wing and tail will be different than a flying wing, which will different from a canard....
Conventionals also have various wing configurations.. straight with no taper, tapered, swept forward or aft.. these all can have c.g.s.
There's some spreadsheet calculators that will handle most of this stuff.
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But lacking any of these, what works on one plane will work on another plane of the same configuration.
The shape you're using would be needed to make any suggestions.