I’m looking to book accommodations in San Diego in a few weeks and noticed that sometimes it can be really frustrating to book hotels in cities during conferences and festivals, since nearly everything can be sold out.

This has happened to me in Munich during Oktoberfest and Rio during Carnivale and recently hit blogger Lucky on his way from Sicily back to the US through Cologne.

So I was pretty delighted to find a tool on Booking.com that will show you the % of hotel space booked for a city for a given date pair. Under 30%? You’re probably fine. 95%? Snag that room before they have you sleeping in the basement!

Here’s a screenshot of this tool:

Good to know I’m not going to be sleeping on the streets even if I wait to book!

It’s worth noting that this feature doesn’t work for every city, but I had pretty good success with developed hotel markets in the US and Europe.

Hopefully, this will help you plan your travel and understand where constraints and hidden costs lie!