What is the customary tip on a buffet?

Servers even on a buffet line only make $2.14 USD an hour if they keep my soda filled and clear empty plates I tip $4-$5 if they provide minimal service and I have to refill my own drink $2 just because I have been there, and then I give the busboy $2 (directly to him)just because he is getting the short end all the way around it doesn't matter if it's lunch buffet or dinner rush he isn't making anymore.

Since I usually give 20% ( more for excellent service) to be waited on, I'll give 10 - 15% for a buffet depending on the service rendered.

10%

I usually go $1-2 per person. They are not doing much for the money. And in most cases, they don't even refill drinks.

Usually around 10% or a $1 per person, but it depends on if they refill drinks vs. a refill yourself place, if/how often they check on us, etc.

I tip about 10-15% of the total bill, depending on service.

Well not much, they don't serve you food. I say a buck a person

I agree with Alessa su.

usually give them about 2 or three dollars.

10% should be fine..