Pendant light? 30 to 40 inches above table, but

The general rule for the height of a pendant light is between 30" to 40" above the surface of the peninsula or
island. However, kitchen islands and peninsulas are highly interactive areas where family and guests will gather.

You'll have to consider the heights of people in your household and their interactions with others who are across from them at your kitchen peninsula or island.

I suggest that you print and read the article about pendant lights at http://www.millennialliving.com/Activities/Renovation/Kitchen/buying-hei.... Just follow the directions there.