This calculator will tell you how much a meeting costs in payroll dollars: here. It was referenced in GapingVoid's cartoon Friday, along with this INC magazine infographic of what an unproductive meeting costs.
All the experts agree that meetings should have an agenda, be short, be structured, start and end on time, and this: No Chairs, No drinks, No phones, No laptops. Why? Stay focused, don't get settled in, Just Get it done.
INC says have "purpose, benefit, check", clear goal and an ask.
I have been in meetings all day at some companies. That's fine since I am only in town for a short time. Yet when I was on longer projects in Cali and Chicago, every day was filled with meetings. Meetings that were useless, mandatory, and some canceled after the start time. It's a sign of a dysfunctional organization and a lack of leadership.
I am all for a 12 minute meeting standing up. Harvard Business has a one-pager on meetings.
How other tech companies handle meetings including Google, Apple and 37Signals.