Welcome to Sailnet, you can learn alot here. Go to this calculator: Sail Calculator Pro v3.53 - 2500+ boats
and you will find that your capsize factor is 2.17. 2.0 and lower are considered good.
It is pretty hard for the wind alone to capsize your keel boat, it may knock you down, ie put the mast head in the water, but it would take a combination of wind and wave to turn you completely over.