SOF - DEN

$457 Find Cheap Flights from Sofia to Denver - Compare and Save

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Sofia to Denver departing on 9/14. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

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Everything you should know

Cheapest round-trip
$939
Typical prices: $751-$850
Lufthansa
Thu 9/3Wed 9/9
SOF - DEN • 1 stop
Cheapest one-way
$457
Multiple Airlines
Mon 9/14
SOF - DEN • 3 stops
Top airlines
Cheapest • from $939 (round-trip)
Best reviews • 7.4 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Nonstop flights
Not available
There are currently no direct flights between Sofia and Denver. You'll need at least 1 connection.
Insights
Insights
Insights
Insights
Top layover airports
Cheapest • Avg $869 (round-trip)
Shortest trip • 16h 25m (one-way)
Insights
Insights
Insights
Insights
When to travel
Cheapest • 100% price drop
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
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We hope you love your trip to Denver!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Sofia to Denver (SOF-DEN)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Sofia to Denver that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Sofia to Denver

Thu, Sep 3 - Wed, Sep 9
Lufthansa Logo
6:30 am - 3:40 pm
SOF
-
DEN
18h 10m
1 stop
Lufthansa Logo
5:40 pm - 10:50 pm
DEN
-
SOF
20h 10m
1 stop
$939Lufthansa
Thu, Sep 3 - Wed, Sep 9
Lufthansa Logo
6:30 am - 3:40 pm
SOF
-
DEN
18h 10m
1 stop
Lufthansa Logo
5:40 pm - 10:50 pm
DEN
-
SOF
20h 10m
1 stop
$943Lufthansa
Thu, Sep 3 - Wed, Sep 9
Multiple Airlines Logo
6:30 am - 3:40 pm
SOF
-
DEN
18h 10m
1 stop
Multiple Airlines Logo
8:25 pm - 11:55 pm
DEN
-
SOF
18h 30m
2 stops
$946Multiple Airlines
Thu, Aug 27 - Wed, Sep 2
Lufthansa Logo
6:30 am - 3:40 pm
SOF
-
DEN
18h 10m
1 stop
Lufthansa Logo
3:55 pm - 6:05 pm
DEN
-
SOF
17h 10m
1 stop
$957Lufthansa
Thu, Sep 3 - Wed, Sep 9
United Airlines Logo
6:30 am - 3:40 pm
SOF
-
DEN
18h 10m
1 stop
United Airlines Logo
8:00 am - 6:40 pm
DEN
-
SOF
25h 40m
2 stops
$958United Airlines
Thu, Aug 27 - Wed, Sep 2
United Airlines Logo
6:30 am - 1:30 pm
SOF
-
DEN
16h 00m
1 stop
United Airlines Logo
9:40 am - 6:05 pm
DEN
-
SOF
23h 25m
2 stops
$960United Airlines
Thu, Aug 27 - Wed, Sep 2
United Airlines Logo
6:30 am - 1:30 pm
SOF
-
DEN
16h 00m
1 stop
United Airlines Logo
8:00 am - 6:40 pm
DEN
-
SOF
25h 40m
2 stops
$962United Airlines
Thu, Sep 3 - Wed, Sep 9
United Airlines Logo
6:30 am - 6:25 pm
SOF
-
DEN
20h 55m
2 stops
United Airlines Logo
3:40 pm - 6:40 pm
DEN
-
SOF
18h 00m
2 stops
$968United Airlines
Thu, Sep 3 - Wed, Sep 9
United Airlines Logo
6:30 am - 6:25 pm
SOF
-
DEN
20h 55m
2 stops
United Airlines Logo
3:40 pm - 6:40 pm
DEN
-
SOF
18h 00m
2 stops
$970United Airlines
Thu, Aug 27 - Wed, Sep 2
United Airlines Logo
6:30 am - 6:19 pm
SOF
-
DEN
20h 49m
2 stops
United Airlines Logo
3:40 pm - 6:40 pm
DEN
-
SOF
18h 00m
2 stops
$972United Airlines
Booking Insights

KAYAK's insights & trends for Sofia to Denver flights

Get data-powered insights and trends into flights from Sofia to Denver to help you find the cheapest flights, the best time to fly and much more.

How much is a round-trip flight from Sofia to Denver?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Sofia to Denver departing in September.

Flight prices are below average for this route right now.

Flights to Denver from Sofia usually cost between $1,087 and $1,154 in September.
The lowest price found in the past 5 days was $939 on Lufthansa (Sep 3-Sep 9).

What is the cheapest month to fly from Sofia to Denver?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Sofia to Denver, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Sofia to Denver is January, where tickets cost $0 (return) on average. On the other hand, the most expensive months are July and June, where the average cost of round-trip tickets is $1,214 and $1,179 respectively.

Good to know

Low season

September

Cheapest flight

$457
Best time to beat the crowds with an average 20% drop in price.
Most popular time to fly and prices are also 20% lower on average.
Flight from Sofia to Denver

When to book flights from Sofia to Denver

Are your dates flexible? Find out the best times to travel from Sofia to Denver based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from Sofia to Denver

  • What is the cheapest flight from Sofia to Denver?

    In the last 5 days, the lowest price for a flight from Sofia to Denver was $457 for a one-way ticket and $939 for a round-trip.

  • Do I need a passport to fly between Sofia and Denver?

    Yes, you’ll need a passport to travel to Denver from Sofia.

  • Which aircraft models fly most regularly from Sofia to Denver?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from Sofia to Denver?

    Star Alliance is the only airline alliance operating flights between Sofia and Denver.

  • Which is the best airline for flights from Sofia to Denver, Turkish Airlines or United Airlines?

    The two airlines most popular with KAYAK users for flights from Sofia to Denver are Turkish Airlines and United Airlines. With an average price for the route of $865 and an overall rating of 7.4, Turkish Airlines is the most popular choice. United Airlines is also a great choice for the route, with an average price of $974 and an overall rating of 7.4.

  • How does KAYAK find such low prices on flights from Sofia to Denver?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Sofia to Denver.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Sofia to Denver?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Denver from Sofia is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Sofia to Denver?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Denver with an airline and back to Sofia with another airline. Booking your flights between Sofia and DEN can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Sofia to Denver?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Denver from Sofia up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top 3 airlines serving from Sofia to Denver

 
See real verified KAYAK customer reviews for airlines flying from Sofia to Denver. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Sofia to Denver? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.4
Turkish AirlinesOverall score based on 4455 reviews
7.3Comfort
7.3Boarding
7.8Crew
7.5Entertainment
7.5Food
Airline reviews

The rules regarding business class lounge hotel/room access were very confusing. Between flights we had an 11 hour layover in Istanbul, but were denied a room to rest as our layover was too long?? Keep in mind that we arrived there at 3:30am after a long flight. Even multiple Turkish airlines employees were inconsistent with the rules. We ended up paying a high price at the Yotel in the airport in order to get some rest. Good thing I did, as a medical emergency was declared on the flight from Istanbul to Atlanta and I was apparently the only physician on board. Luckily I was able to stabilize the passenger and the flight wasn't diverted. The crew called an overhead announcement for a medical doctor, but insisted that I show them a copy of my medical license which I did. Very strange in my 35 years as a physician and responding multiple times to inflight medical emergencies over the years. I was very glad the passengers issue was resolved, but an acknowledgement of at least a thank you from the crew would have been appreciated.

10.0 ExcellentStephen, Jul 2026
IST - ATL
Read more Turkish Airlines reviews

The rules regarding business class lounge hotel/room access were very confusing. Between flights we had an 11 hour layover in Istanbul, but were denied a room to rest as our layover was too long?? Keep in mind that we arrived there at 3:30am after a long flight. Even multiple Turkish airlines employees were inconsistent with the rules. We ended up paying a high price at the Yotel in the airport in order to get some rest. Good thing I did, as a medical emergency was declared on the flight from Istanbul to Atlanta and I was apparently the only physician on board. Luckily I was able to stabilize the passenger and the flight wasn't diverted. The crew called an overhead announcement for a medical doctor, but insisted that I show them a copy of my medical license which I did. Very strange in my 35 years as a physician and responding multiple times to inflight medical emergencies over the years. I was very glad the passengers issue was resolved, but an acknowledgement of at least a thank you from the crew would have been appreciated.

I wasn't able to bring my little dog with me, because of the feedback team's extremely slow response. How are they even allowed to operate with this paste??

The sleeper seats, the staff, and the food was truly delicious. I loved the mocktail options.

Great service. Seat was a bit small but it was fine. Food was great

Horrible service at the baggage claim. Stuck on plane for an hour due to taxing and no gate.

The crew was awesome. My husband fell while traveling to the WC and got a head abrasion. The crew helped him greatly and a physician that was also on the flight checked him out as well. They all get an A+!

The seats were extremely small. Boarding was not communicated correctly. It wasn’t a pleasant trip.

Loved the food. No wheelchair was provided in Sofia even though wheelchair assistance was confirmed by Turkish Airlines

Same as before boarding process and lack of crew experience in the process

Excellent service. Made United 's business class look like a cattle car

Lufthansa seats were much more comfortable than United. While they had about the same video selection, Lufthansa didn't put advertisements in with the movies like United did. And the Lufthansa food was much better than United.

We flew business fares. Was amazing. However, the check in didn't offer business fares preboarding which is less hectic. 8/10 due to this. Staff compared to Canadian carriers go above and beyond. Would gladly fly United again.

The staff was incredible, very attentive, polite, made you feel like the center of the universe. They even all wrote me a happy birthday card. Truly just an amazing crew, cannot stress it enough.

Checking bag at terminal was horrible. No agents to check us in and only 1 kiosk working. Boarding went ok. Crew onboard was very scattered rained. Missed our row while serving and then didn’t see them hardly again.

The entertainment is a bit limited, it would be better if they added some games to play besides the movies and tv shows. But the seats are comfortable and the crew is polite

Food was great. Staff was phenomenal. Seats were a bit hard and could use a lot more entertainment options as far as movies to choose from. WiFi was good. Overall great trip.

Boarding was smooth and efficient. The only food was some pretzels, but it was a short flight. Not much to order if you were hungry.

Read the fine print. This was my flight home. I booked my flight for the quickest way home. Had a carry-on and a personal item. Same as my outbound flight. Apparently I needed to pre-pay extra for my carry-on. When I checked in, I was told that I had to check it. I said I’ll pay for it, and was told that this wasn’t an option anymore. They said I still had to pay $50 to check my carry-on. I told them I’ll pay whatever to just carry it in as intended. I was not allowed, so eventually I paid $50 to check my carry-on under a plane that was half full, with overhead compartments that were even less full. My white carry-on suitcase was practically destroyed getting from Idaho falls to Denver to Orange County. The low price air fair was a bait and switch. Got me to the gate, made me pay extra, then didn’t even allow me to pay for a carry on. Not to mention that I paid the $8 for WiFi that didn’t work. All to get my suitcase destroyed. I don’t think I’m going to even keep my Untied mileage plus membership and card. Apparently, membership does not have its privileges for this one.

I flew from Santa Fe to Denver to catch a flight to London and the transfer of my luggage on arrival at Denver to the London flight worked perfectly. The crew on the ground and on board for the London flight were so friendly and efficient.

Late- that’s what United does best. Missed my connection, rebooked to a flight 17 hours later and had to spend $500 on a hotel. What did I get? A $15 meal voucher. What can you get in an airport for $15. I hate United so much.

I liked the flight, the attendants, and the comfort. But the gate for boarding was poor. Even the elderly had to climb down many many steps to the bus and climb up to the plane.

Service was excellent. Flight was only about half full, which meant we had tons of room to stretch out. Boarding area was nice and well organized, flight attendants were super friendly and attentive and we loved the 3 snacks!

Lufthansa is turning into a budget airline. On transfers, the luggage never arrives if you have less than 2 hours for the transfer. This is happened to me multiple times when I end up on flights serviced by Lufthansa. The first leg of the flight was serviced by Discover Airlines. It was a 3-hour flight and they only offer a glass of water. Everything else is for purchase. I purchased my ticket as economy which should have included a bag but it ended up booking as economy light so I had to pay for a bag in each direction.

The food that was served was superb!!! Awesome snacks!!! Frequent drink service!!! To me, this was shocking. I took a British Airways flight from Denver to London for the first leg of my trip and the food was horrendous. Thank you for keeping us fed and satiated on such a long flight!!!!

It was freezing. I asked crew member for a blanket and was told it might be in front of plane but I never got one. I turned off all the vents but still froze.

My flight was delayed d the gate was never updated inside the terminal. If I hadn’t checked my email I would have missed my flight. Also, I paid a total of $5100 for my flight to be. Business or first class. My final leg of my flight from Heathrow to Frankfurt was not to standard of what I expected or experienced in the previous legs of my trip.

I think it was a United A380 plane. The trip from Munich to Denver was about 12 hours and the preferred economy seat I paid $75 for was very cramped. The crew was nice but I was so uncomfortable and getting up to walk around didn’t really help. My legs were swollen for 4 days afterward. I would think on such a long trip the seats would have more room. I would have gone 1st class but it was 3-4 times more expensive. I won’t fly anywhere far away again. My last experience with Lufthansa was great to Italy and back, but this time I could swear everything was United and not good.

Not good. They charged an additional $70 to check a bag we had already paid for on line with Lufstansa

This flight went smoothly and the economy plus free upgrade worked very well.

The hot towels before the second meal was an unexpected surprise. The crew was attentive and personable, and that’s a lot on a nine hour flight. And the hot pretzels were a kind of “auf wiedersehn “ to Germany.

Everything you need to know for your flight from Sofia to Denver

Information on your arrival and departure airports