Need help booking?
Unpublished phone-only deals available
KLS to SOF: distance & flight time
Kelso (Southwest Washington Regional Airport) → Sofia (Sofia Airport)
5,961 mi
9,594 km · 5,180 nm
12h 9m
estimated nonstop flight time
+10h
time difference · heading northeast
See live KLS→SOF fares Phone-only fares on this route — call free
Flight time details
5,961 miles nonstop takes roughly 12h 9m gate to gate, flying northeast. Add 45–90 minutes per connection if there's no nonstop service. Remember to factor the 10-hour time gain when reading arrival times on your ticket.
The two airports
- KLS — Southwest Washington Regional Airport · Kelso, United States
- SOF — Sofia Airport · Sofia, Bulgaria
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 KLS
- PDX · Portland International Airport39 mi away
- CLS · Chehalis Centralia Airport39 mi away
- HIO · Portland Hillsboro Airport40 mi away
- TTD · Portland Troutdale Airport46 mi away
Near SOF
- PDV · Plovdiv International Airport85 mi away
- INI · Nis Airport90 mi away
- SKP · Skopje Alexander the Great Airport105 mi away
- CRA · Craiova Airport115 mi away
Frequently asked questions
How far is KLS from SOF?
The flight distance from Kelso (KLS) to Sofia (SOF) is 5,961 miles (9,594 km, 5,180 nautical miles), measured along the great-circle route airlines actually fly.
How long is the flight from KLS to SOF?
A nonstop flight takes about 12h 9m 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 Kelso and Sofia?
Sofia is 10 hours ahead of Kelso.
What is the cheapest way to fly from KLS to SOF?
Compare live fares online, then call CheapoTrav — our agents have unpublished consolidator fares on KLS–SOF that never appear on search engines, with no booking fees.