How much can you give employees in benefits (without tax effects)?

I work at a startup in California, USA.

I know that whenever I go out to lunch with my CEO, he says he is only allowed to expense the meal if it was "business related," like meeting clients or something. At the same time, I know Google gives the employees free meals.

How much can you give employees in perks, before you have to start declaring it as compensation and they pay taxes on it?

I don't know about cali law but what you are talking about is knows as "Fringe Benefits" by the IRS. Their documentation is a bit vague on the whole deal, I.E. they don't set any exact dollar values, but they basically say that if it's an occasional, non-company policy thing you don't need to report it as taxable. If it's a set policy or written perk then you have to report it as taxable on the employees.

so in your example, lunches with the CEO aren't worth reporting because the taxable value is probably so small it's not worth the time it will take to calculate and report on it. However, google providing free lunch every day would have to report the cost to the IRS for you.

Here's a pdf doc with more info.