Mae Sot to YangonFrom Mae Sot to Yangon
Receive a warning when the price falls from Mae Sot to Yangon (Rangoon). The rates are on a return journey with a return journey between 1-21 nights after your arrival. Tickets are subject to rapid changes and cannot be guarantee. Rangoon Yangon is 7 miles from Mingaladon Airport (Yangon, Myanmar).
Currently 49 carriers are operating from Mingaladon Airport. The airport Mingaladon has non-stop services to 33 towns. There are at least 211 national and 392 intercontinental departures per weeks from Mingaladon Airport.
Mae Sot overland border crossing at Thorn Tree
When the Chiang Mai OR wants to get to Yangon in the shortest possible timeframe, it is very simple and does not take much of your schedule. I have Bangkok to Hpa-an and many others, Kawkareik to Bangkok (via the old road) and will take Mawlamyine to Bangkok in one afternoon, although not by means of local transportation, but all these combination are much further than Chiang Mai to Hpa-an via Mae Sot and in all cases I have been able to reach my goal not too far in the morning.
Like Rivaltribal said, Chiang Mai to Mae Sot lasts only 5-6 hrs by coach and then it is only about 3 hrs to Hpa-an after you cross the boarder, which doesn't take more than a few minutes. It is usually quite simple to depart almost immediately after arrival in Myawady, and if there are no other travelers, simply charter a cab or find other travelers who also cross and you can depart almost immediately.
Then Hpa-an to Yangon is only 5-6 hrs by coach or only 4.5 hrs by cars. All in all it is about 3+5 or 3+6, so let's say 9 hrs from Myawady via Hpa-an to Yangon. The drive over the island is longer, because it is a small roundabout, but it is not longer than oneh.
Probably most travelers would want to try Hpa-an or Marlamyine as a stop between Chiang Mai and Yangon, although Hpa-an is more interesting. Both Mae Sot and Myawady would have little interest, although both places have some interesting things to see/do. So 2 or 3 day are very real, 3 only if you want to try Hpa-an on the road.
As an alternative, Golden Rock is another intermediate stop along the motorway between Myawady and Yangon. For a fast passage 2 or less day are possible; 3-4 day (or more) to really see places in between (mainly Hpa-an, maybe Mawlamyine and Kyaithiyo (Golden Rock)).