How long does it take to get through customs at 12 noon in Paris (CDG)?

Not long at all, usually. There is generally a line at passport control and then a wait for your luggage to arrive at the baggage carousel. I would have to say that customs itself is pretty benign, since I've gone through 14 times and never even had to break the pace of my walk. I suppose I would allow for 45 minutes to be on the safe side, but I doubt that you would typically need all of that time. You may hear some horror stories about bad days and I'm sure they have occurred, but that is not typical. (I've always gone through CDG-1). If you are asking because you are making a transfer to another flight, then that is a different matter than if you are simply leaving to go into Paris.

Are you intrested in Customs only - or also Immigration. In my experience - Immigration is where you usually find the delay - depending on how many flights come in at once (we once waited over 1.5 hours when a couple of planes from Africa landed just ahead of us).

I'll assume you mean immigration. Customs is where they check whether what you are bringing into the country is OK -- Immigration is where they check that YOU are OK.

Anyway - there is really no way to tell you precisely what noon on a ceratin day will be like. A lot depends on from where other flights are arriving at around the same time.

Count on 60 to 90 mins for customs/immigration/hitting the ATMs and if it is less be happy.

The longest wait I've ever had at passport control was about 30 minutes at Terminal 2. Baggage delivery is incredibly fast--speedier than at any other airport I've ever used! I've never been stopped at customs. The trick to not getting stopped by customs is to adopt a travel-weary look on your face, not be overheard speaking French, behave as if you've passed through a thousand times before, and ABSOLUTELY do not make eye contact with a customs officer.

There's an infinitely simpler way of getting through Customs anywhere in civilised Europe without being stopped:

1. Collect your luggage
2. Walk through green channel.
3. There is no 3. Follow 1+2 and no-one will stop you.