This is a tough question and volume changes so much of it. The standard business model is 30% COGS (Cost Of Goods Sold), 30% Labor, 30% Operational Expenses and (hopefully!) 10% profit.
I feel like labor is something that is often over looked, efficiency is the key to any successful operation and that labor can drop fast if you have things set up correctly and have a well trained staff. On high volume days, I can drop as low as 12% labor with me working in the kitchen, 20% without. The problem, which I have constantly struggled with, is consistency. I could probably run around 20% without me there pretty regularly…and I’m slowly getting there, but you have to have a tight schedule, especially before you open your doors and be sure every hour on the clock is being fully utilized.