Hi,

Dimensions & proportions are only one consideration for deciding on lighting.

• Is this dining room open to other spaces or closed off behind a door(s)?

• What style of decor is in this room?

• What finishes are in this room - light or dark, highly reflective or not, etc?

• Do you wish to have direct or in-direct lighting?

As for spacing, there is no hard/fast rule. It'll be determined by answering the above and by deciding on the fixture before you decide the height above the table. For a fixture with exposed bulbs you might hang higher to help avoid glare. If the room has a great view out to other spaces or outdoors you may hang higher as well. If you're hoping to create a more intimate setting, the right type of fixture might hang lower.

Good luck!