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USM to STL: distance & flight time
Ko Samui (Samui Airport) → St. Louis (St Louis Lambert International Airport)
9,033 mi
14,537 km · 7,849 nm
18h 11m
estimated nonstop flight time
-12h
time difference · heading north
See live USM→STL fares Phone-only fares on this route — call free
Flight time details
9,033 miles nonstop takes roughly 18h 11m gate to gate, flying north. Add 45–90 minutes per connection if there's no nonstop service. Remember to factor the 12-hour time set-back when reading arrival times on your ticket.
The two airports
- USM — Samui Airport · Ko Samui, Thailand
- STL — St Louis Lambert International Airport · St. Louis, United States
Distances are great-circle ("as the crow flies") — the same basis airlines use for frequent-flyer miles.
Alternate airports can cut this fare
Flying from or into a nearby airport is the #1 trick our agents use to beat online prices. Call and we'll compare every combination on one call.
Near USM
- URT · Surat Thani Airport69 mi away
- NST · Nakhon Si Thammarat Airport70 mi away
- CJM · Chumphon Airport93 mi away
- UNN · Ranong Airport102 mi away
Near STL
- SUS · Spirit of St Louis Airport16 mi away
- ALN · St Louis Regional Airport20 mi away
- BLV · Scott AFB/Midamerica Airport32 mi away
- SPI · Abraham Lincoln Capital Airport84 mi away
Frequently asked questions
How far is USM from STL?
The flight distance from Ko Samui (USM) to St. Louis (STL) is 9,033 miles (14,537 km, 7,849 nautical miles), measured along the great-circle route airlines actually fly.
How long is the flight from USM to STL?
A nonstop flight takes about 18h 11m gate to gate. Actual time varies with winds, routing and season — eastbound transatlantic flights, for example, are usually faster than the return.
What is the time difference between Ko Samui and St. Louis?
St. Louis is 12 hours behind Ko Samui.
What is the cheapest way to fly from USM to STL?
Compare live fares online, then call CheapoTrav — our agents have unpublished consolidator fares on USM–STL that never appear on search engines, with no booking fees.