Good question with a simple answer.
The Convention Calendar search page (www.lvcva.com/meetings/convention-calendar.jsp) on the Las Vegas Concention and Visitors Authority Web site provides a complete listing of more than 1,000 conventions at nearly 100 meeting venues from the current date through 2021 (yes, 1,800 attendees are scheduled to meet at Caesars Palace, August 3-14, 2021, for the National Convention of the Association Of Latino Professionals In Finance & Accounting).
The search function allows you to look for the name (part or full) of the convention, the exact dates (through 2017), and the venues, everything from the Alexis Park to the Wynn and Lake Las Vegas and Mesquite to Laughlin.
You can click on View All Conventions, then select Show All at the bottom of that page, by which you can scroll through an epic list of every convention currently scheduled and see the group, venue, start and end dates, and most importantly, the number of attendees (everything from 12 Wicklander-Zulawski & Associates conventioneers meeting at Hooters November 10-11, 2008, all the way up to 148,000 -- and counting -- for the 2009 Consumer Electronics Show at the Las Vegas Convention Center January 8-11, 2009).
Another way to find out about conventions, special events, and the like that impact room rates is to phone up hotel reservations departments and ask for the rates for the particular dates you're thinking about for your trip. If they seem higher than expected, your first question should be, "Is something big happening at your hotel or in Las Vegas during those dates?" Reservation agents are usually pretty plugged in to the reasons why rates might be high, higher, or highest at any given time.
Last but not least, we list all conventions with 10,000 or more attendees right here on our site in the LVA Visitor Guide for the very same reason. The vast majority of these expos and meetings are open only to registered attendees, but we know the impact the big ones have on room rates and availability, which is why we keep up to date with them.
