How long should one allow to travel from Don Muang to Suvarnabhumi?

i think the actual trip is probably not more than one hour but i should think you need to think in terms of 2-3 hours total...

locals will make more positive suggestions: michaelbkk and jamesA among others

We actually did this trip 2 weeks ago when our connecting flight to Chiang Rai was moved back to Don Muang. we hit the taxi rank at Suvarnabhumi at 16.00 on Friday afternoon and 35 minutes later we were checking in at Don Muang. The tax cost 250bht. The guy at the taxi rank did warn us that it would take 2 hours. Maybe we were just lucky with the traffic.

Thanks very much! That's just what I wanted to know. Unfortunately it means the itinerary I was hoping for might very well not work, so back to the drawing board....

33 minutes is what it will take by taxi most of the time, run into heavy traffic and it could take up to an hour. Thai Airways have a connecting coach for their customers but l've heard it's pretty slow for some reason.