Need help booking?
Unpublished phone-only deals available
SPF to USM: distance & flight time
Spearfish-South Dakota (Black Hills Airport-Clyde Ice Field) → Ko Samui (Samui Airport)
8,417 mi
13,546 km · 7,314 nm
16h 58m
estimated nonstop flight time
+13h
time difference · heading northwest
See live SPF→USM fares Phone-only fares on this route — call free
Flight time details
8,417 miles nonstop takes roughly 16h 58m gate to gate, flying northwest. Add 45–90 minutes per connection if there's no nonstop service. Remember to factor the 13-hour time gain when reading arrival times on your ticket.
The two airports
- SPF — Black Hills Airport-Clyde Ice Field · Spearfish-South Dakota, United States
- USM — Samui Airport · Ko Samui, 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 SPF
- RCA · Ellsworth Air Force Base41 mi away
- RAP · Rapid City Regional Airport47 mi away
- GCC · Gillette Campbell County Airport87 mi away
- CDR · Chadron Municipal Airport119 mi away
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
Frequently asked questions
How far is SPF from USM?
The flight distance from Spearfish-South Dakota (SPF) to Ko Samui (USM) is 8,417 miles (13,546 km, 7,314 nautical miles), measured along the great-circle route airlines actually fly.
How long is the flight from SPF to USM?
A nonstop flight takes about 16h 58m 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 Spearfish-South Dakota and Ko Samui?
Ko Samui is 13 hours ahead of Spearfish-South Dakota.
What is the cheapest way to fly from SPF to USM?
Compare live fares online, then call CheapoTrav — our agents have unpublished consolidator fares on SPF–USM that never appear on search engines, with no booking fees.