There are online CofG calculators to estimate it. One this I should say is that your vertical stabilisers will not work well as they are almost certainly mostly in front of the CofG and will actually make it unstable in yaw.
QUOTE="Fluqok, post: 497724, member: 29128"]I found a calculator but it could only do delta wings so not with the thing in the middle can I just use that one or is that not possible?[/QUOTE]
As it's not swept back you can pretty much ignore it and still be on the ball park.