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FSI to CEI: distance & flight time
Fort Sill (Henry Post Army Air Field (Fort Sill)) → Chiang Rai (Chiang Rai International Airport)
8,478 mi
13,643 km · 7,367 nm
17h 5m
estimated nonstop flight time
+12h
time difference · heading north
See live FSI→CEI fares Phone-only fares on this route — call free
Flight time details
8,478 miles nonstop takes roughly 17h 5m gate to gate, flying north. Add 45–90 minutes per connection if there's no nonstop service. Remember to factor the 12-hour time gain when reading arrival times on your ticket.
The two airports
- FSI — Henry Post Army Air Field (Fort Sill) · Fort Sill, United States
- CEI — Chiang Rai International Airport · Chiang Rai, Thailand
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 FSI
- LAW · Lawton Fort Sill Regional Airport6 mi away
- DUC · Halliburton Field28 mi away
- HBR · Hobart Regional Airport44 mi away
- SPS · Sheppard Air Force Base-Wichita Falls Municipal Airport46 mi away
Near CEI
- THL · Tachileik Airport37 mi away
- HOE · Ban Huoeisay Airport42 mi away
- MOG · Mong Hsat Airport56 mi away
- KET · Kengtung Airport95 mi away
Frequently asked questions
How far is FSI from CEI?
The flight distance from Fort Sill (FSI) to Chiang Rai (CEI) is 8,478 miles (13,643 km, 7,367 nautical miles), measured along the great-circle route airlines actually fly.
How long is the flight from FSI to CEI?
A nonstop flight takes about 17h 5m gate to gate. Actual time varies with winds, routing and season — eastbound transatlantic flights, for example, are usually faster than the return.
Are there nonstop flights from FSI to CEI?
Nonstop service on FSI–CEI depends on the season and the day of week. Run the fare search on this page with the nonstop filter applied to see current direct options; when there is no nonstop, a single connection through a carrier hub adds roughly 2–4 hours to the 17h 5m nonstop estimate.
What is the time difference between Fort Sill and Chiang Rai?
Chiang Rai is 12 hours ahead of Fort Sill.
What is the cheapest way to fly from FSI to CEI?
Compare live fares online, then call CheapoTrav — our agents have unpublished consolidator fares on FSI–CEI that never appear on search engines, with no booking fees.
Why are some FSI to CEI fares phone-only?
Consolidator contracts let us sell certain FSI–CEI tickets below the price airlines permit us to publish online, so those fares can only be quoted over the phone. Call the travel desk and an agent will check phone-only inventory for your dates.