How much time to make a US-bound flight?
 

I'll be visiting in the fall and am trying to figure out how long I should allocate in order to make a US-bound flight out of YYZ. Ideally, I'd like a sense of how late I could leave the Sheraton Centre in the evening and make, say, an 8pm flight. 2 hours? 3?

You'll have to go through US customs as well as normal security. If you don't have a NEXUS card then it is hard to predict the time. Arriving at the airport 90 minutes ahead of the flight would probably be safe. That puts your drive to the airport at rush hour where an hour is normal. That adds up to 2.5 hours. Make it 3 if you want to be safe. You'll have to be checked out of the hotel earlier anyway. The Airport Express is a good bet from the Sheraton and the drivers are very experienced on the route, so ask them when you reserve the ticket.

How about if I have a NEXUS card?

jmr50 since you are looking at an 8 pm flight i would leave around 6 pm or so. If you OLCI you could push it to 6:15 as it might take you about 45 to 60 minutes to get to YYZ from the Sheraton at that time.

Then you can arrive at the airport one hour ahead of the flight. Figure that NEXUS saves 30 minutes. But the less close you cut it, the less pressure.

I would still give myself plenty of time for the CATSA security check post US CBP clearance.

Since it is an evening flight you would hate to miss it and check into another Sheraton(YYZ) for the night.

The cut off time for checked baggage is 1 hr before the flight so you probably don't want to arrive 1 hour before the flight, unless of course you have no checked baggage then 1 hr works fine