We have 2 fixtures to hang in our kitchen. We have 8 foot ceilings, if it matters. One will hang centered over the island and one will hang over our kitchen table. Is there a rule of thumb regarding how low the bottom of these fixtures should be from surface that they are lighting?

There is no rule of thumb here. There is the rule of hitting your head though on the fixture if some family member is tall. I am short and in my home I replaced all my ceiling light fixtures with chandeliers and happily walk underneath them. When I have company over I almost have to place "Caution Watch Your Head" signs on them for the tall folks.

Also, if you are just using the light for dining purposes, experiment with different heights for the lights during the evening hours when you would be using the dining table and see if there is too much glare having the fixture up too high. Same goes for the island. Experiment when it's dark out so you can get the full effect of the light.

Twinkie gave some good advice I however have the opposite problem Im over 6 ft tall so no hanging fixtures in my house are less than 7ft off the floor except the light right over the dining room table which is 6ft off the floor. Personally I like to have about 4ft between the table and the light but that's just me . Follow the above advice and remember to select a light that's easily kept clean nothing worse than eating dinner and looking up to see a mass of dust hanging from your light. I used to have a very ornate chandelier hanging over my table and it was a nightmare to keep clean. Just my two cents GOOD LUCK,AC

Thanks twinkie and ac! My husband and I are on the shorter side, but our relatives and male guests seem to all be on the tall side. Since we usually use our island as a serving station when entertaining, I want to make sure the island double pendant does not get in the way. Leaning towards about 35 inches above the countertop. Our lighting salesperson suggested the bottom of the fixture should be even with the bridge of your nose. But that seems REALLY low.

We will try at various heights to see what works best. Thanks again!