Need help booking?
Unpublished phone-only deals available
USN to ONT: distance & flight time
Ulsan (Ulsan Airport) → Ontario (Ontario International Airport)
5,972 mi
9,611 km · 5,190 nm
12h 11m
estimated nonstop flight time
-16h
time difference · heading northeast
See live USN→ONT fares Phone-only fares on this route — call free
Flight time details
5,972 miles nonstop takes roughly 12h 11m gate to gate, flying northeast. Add 45–90 minutes per connection if there's no nonstop service. Remember to factor the 16-hour time set-back when reading arrival times on your ticket.
The two airports
- USN — Ulsan Airport · Ulsan, South Korea
- ONT — Ontario International Airport · Ontario, 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 USN
- KPO · Pohang Airport (G-815/K-3)28 mi away
- PUS · Gimhae International Airport37 mi away
- TAE · Daegu Airport44 mi away
- CHF · Jinhae Airbase/Airport (G-813/K-10)48 mi away
Near ONT
- CCB · Cable Airport6 mi away
- CNO · Chino Airport6 mi away
- LAX · Los Angeles International Airport47 mi away
- RAL · Riverside Municipal Airport11 mi away
Frequently asked questions
How far is USN from ONT?
The flight distance from Ulsan (USN) to Ontario (ONT) is 5,972 miles (9,611 km, 5,190 nautical miles), measured along the great-circle route airlines actually fly.
How long is the flight from USN to ONT?
A nonstop flight takes about 12h 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 Ulsan and Ontario?
Ontario is 16 hours behind Ulsan.
What is the cheapest way to fly from USN to ONT?
Compare live fares online, then call CheapoTrav — our agents have unpublished consolidator fares on USN–ONT that never appear on search engines, with no booking fees.