The industry standard answer is "28–32%" — but that number is almost useless without context. A breakfast-focused bagel shop and a seafood restaurant will have wildly different targets based on menu mix, labor model, and concept type.
What actually matters: your theoretical food cost vs. your actual food cost. The gap between those two numbers is where your problem lives.
Theoretical is what you should have spent based on recipes and sales mix. Actual is what came in the back door. If they don't match, something is wrong — waste, over-portioning, theft, or bad receiving.