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$835+ Cheap flights from Bulgaria to Colorado

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 11/15. Fares are subject to change and may not be available on all flights or dates of travel.
SOF — DEN
Nov 12 — Nov 191
Wed 11/12
Wed 11/19
1 adult, Economy
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Find flight deals from Bulgaria to Colorado

Cheapest flights from Bulgaria to Colorado
Explore the most affordable flight options available from Bulgaria to Colorado. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 13, 2025.

This United Airlines deal was found by Cheapflights users on 10/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/156:25 amSOF - DEN
1 stop16h 15mUnited Airlines
Tue 11/257:46 amDEN - SOF
2 stops20h 29mUnited Airlines
Deal found 10/11$835
This United Airlines deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/306:00 amSOF - DEN
1 stop16h 40mUnited Airlines
Wed 11/54:20 pmDEN - SOF
1 stop21h 25mUnited Airlines
Deal found 10/12$836
This United Airlines deal was found by Cheapflights users on 10/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/196:10 amSOF - DEN
1 stop18h 50mUnited Airlines
Wed 11/263:55 pmDEN - SOF
1 stop17h 05mUnited Airlines
Deal found 10/11$837
This Lufthansa deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Lufthansa is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/176:10 amSOF - DEN
1 stop18h 50mLufthansa
Mon 11/248:20 pmDEN - SOF
1 stop17h 25mLufthansa
Deal found 10/12$838
This United Airlines deal was found by Cheapflights users on 10/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/166:10 amSOF - DEN
2 stops27h 05mUnited Airlines
Sun 11/238:20 pmDEN - SOF
1 stop17h 25mUnited Airlines
Deal found 10/11$841
This United Airlines deal was found by Cheapflights users on 10/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/176:10 amSOF - DEN
2 stops20h 48mUnited Airlines
Sun 11/2312:45 pmDEN - SOF
2 stops15h 50mUnited Airlines
Deal found 10/11$843
This United Airlines deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/166:10 amSOF - DEN
2 stops35h 14mUnited Airlines
Mon 11/248:20 pmDEN - SOF
1 stop17h 25mUnited Airlines
Deal found 10/12$844
This Air Canada deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/172:20 pmSOF - DEN
2 stops29h 03mAir Canada
Wed 11/267:05 pmDEN - SOF
2 stops33h 45mAir Canada
Deal found 10/12$845
This United Airlines deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/172:20 pmSOF - DEN
2 stops18h 57mUnited Airlines
Tue 11/259:35 amDEN - SOF
2 stops19h 10mUnited Airlines
Deal found 10/12$849
This United Airlines deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/156:05 amSOF - DEN
1 stop21h 50mUnited Airlines
Mon 11/248:20 pmDEN - SOF
1 stop13h 00mUnited Airlines
Deal found 10/12$851

Cheap flight deals from Bulgaria to Colorado

Keep the following information in mind while searching for Bulgaria to Colorado flight deals. Data was last updated October 13, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$835
(United Airlines)

Popular in

May

Cheapest in

February

Average price

$884
Provider with most accurate pricing for Sofia-Denver Intl flight deals.
Search Deals
Provider most trusted by Cheapflights users for Sofia-Denver Intl flights.
Search Deals
From Bulgaria to Colorado
Search Deals
Highest demand for flights based on searches. 4% potential increase in price ($37 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($23 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in October 2025
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Bulgaria to Colorado that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated October 13, 2025.
Use the filters below to find and compare flights from Bulgaria to Colorado that are best for you.

Fly from

Bulgaria

Fly to

Colorado

Route

Depart

Return

Price

SofiaDenver

SOF - DEN

SOFDEN

Sofia

Wed 11/19

6:10 am-1:40 pm

1 stop16h 30m

Denver Intl

Tue 11/25

9:35 am-1:15 pm

2 stops18h 40m

$835

SofiaDenver

SOF - DEN

SOFDEN

Sofia

Tue 11/18

6:00 am-4:00 pm

1 stop19h 00m

Denver Intl

Mon 11/24

8:20 pm-10:45 pm

1 stop17h 25m

$835

SofiaDenver

SOF - DEN

SOFDEN

Sofia

Sat 11/15

6:25 am-1:40 pm

1 stop16h 15m

Denver Intl

Sun 11/23

8:00 am-1:00 pm

2 stops20h 00m

$835

SofiaDenver

SOF - DEN

SOFDEN

Sofia

Sat 11/15

6:25 am-1:40 pm

1 stop16h 15m

Denver Intl

Mon 11/24

8:20 pm-10:45 pm

1 stop17h 25m

$835

SofiaDenver

SOF - DEN

SOFDEN

Sofia

Tue 11/18

6:00 am-4:00 pm

1 stop19h 00m

Denver Intl

Tue 11/25

8:20 pm-6:20 pm

1 stop13h 00m

$835

SofiaDenver

SOF - DEN

SOFDEN

Sofia

Mon 11/17

6:10 am-4:00 pm

1 stop18h 50m

Denver Intl

Sun 11/23

8:00 am-1:00 pm

2 stops20h 00m

$835

SofiaDenver

SOF - DEN

SOFDEN

Sofia

Tue 11/18

6:00 am-4:00 pm

1 stop19h 00m

Denver Intl

Mon 11/24

7:46 am-1:15 pm

2 stops20h 29m

$835

SofiaDenver

SOF - DEN

SOFDEN

Sofia

Mon 11/17

6:10 am-4:00 pm

1 stop18h 50m

Denver Intl

Wed 11/26

5:45 pm-6:00 pm

1 stop15h 15m

$837

SofiaDenver

SOF - DEN

SOFDEN

Sofia

Wed 11/19

6:10 am-7:55 pm

2 stops22h 45m

Denver Intl

Wed 11/26

12:45 pm-1:50 pm

2 stops16h 05m

$837

SofiaDenver

SOF - DEN

SOFDEN

Sofia

Tue 11/18

6:00 am-4:00 pm

1 stop19h 00m

Denver Intl

Wed 11/26

5:45 pm-6:00 pm

1 stop15h 15m

$837

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/12

Showing 1-10 of 16 results
1
2

Best time to book a flight from Bulgaria to Colorado

Have a flexible travel schedule? Discover the best time to fly to Colorado from Bulgaria with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Bulgaria to Colorado

What is the cheapest month to book a flight from Bulgaria to Colorado?

Currently, December is the cheapest month in which you can book a flight from Bulgaria to Colorado (average of $711). Flying from Bulgaria to Colorado in August is currently the most expensive (average of $834). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from BG to CO?

Find hourly flight availability from Bulgaria to Colorado. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated October 13, 2025.

One of the essential ways to save on airfare from Bulgaria to Colorado is to remain as flexible as possible. Flights that are at noon tend to be the most expensive. A flight in the evening could potentially save you up to 24% on airfare.

Reviews of airlines servicing Colorado

Get insights into the airlines that provide service to Colorado. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Colorado. Reviews last updated October 13, 2025.
Read reviews from past customers who have flown United Airlines, Turkish Airlines, and Lufthansa from Bulgaria to Colorado. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
8,973 reviews

Boarding

7.7

Crew

8.1

Entertainment

7.1

Overall

7.4

Comfort

7.3

Food

6.6

Reviews

1 / 20
8.0
Excellent

Anonymous,Oct 2025

YUL - ORD

Crew and customer service are 5 stars. I had a lot of luggage for a very long trip and they were nothing but helpful and found solutions to every problem. It was my first time flying with United, and they really are the friendly skies. Leg room however, on 2/3 flights was terrible. Same for entertainment: There was only a seat-mounted screen on 1/3 flights. It would have been nice to have on the longest leg of the journey.
United Airlines
7.4
Good
8,973 reviews
United Airlines
7.4
Good
8,973 reviews

Boarding

7.7

Crew

8.1

Entertainment

7.1

Overall

7.4

Comfort

7.3

Food

6.6

Reviews

1 / 20
8.0
Excellent

Anonymous,Oct 2025

YUL - ORD

Crew and customer service are 5 stars. I had a lot of luggage for a very long trip and they were nothing but helpful and found solutions to every problem. It was my first time flying with United, and they really are the friendly skies. Leg room however, on 2/3 flights was terrible. Same for entertainment: There was only a seat-mounted screen on 1/3 flights. It would have been nice to have on the longest leg of the journey.
Turkish Airlines
7.3
Good
4,006 reviews
United Airlines
7.4
Good
8,973 reviews

Boarding

7.7

Crew

8.1

Entertainment

7.1

Overall

7.4

Comfort

7.3

Food

6.6

Reviews

1 / 20
8.0
Excellent

Anonymous,Oct 2025

YUL - ORD

Crew and customer service are 5 stars. I had a lot of luggage for a very long trip and they were nothing but helpful and found solutions to every problem. It was my first time flying with United, and they really are the friendly skies. Leg room however, on 2/3 flights was terrible. Same for entertainment: There was only a seat-mounted screen on 1/3 flights. It would have been nice to have on the longest leg of the journey.
Lufthansa
6.8
Okay
7,476 reviews
United Airlines
7.4
Good
8,973 reviews

Boarding

7.7

Crew

8.1

Entertainment

7.1

Overall

7.4

Comfort

7.3

Food

6.6

Reviews

1 / 20
8.0
Excellent

Anonymous,Oct 2025

YUL - ORD

Crew and customer service are 5 stars. I had a lot of luggage for a very long trip and they were nothing but helpful and found solutions to every problem. It was my first time flying with United, and they really are the friendly skies. Leg room however, on 2/3 flights was terrible. Same for entertainment: There was only a seat-mounted screen on 1/3 flights. It would have been nice to have on the longest leg of the journey.

Related info for your journey

Find useful and relevant information for your journey from Bulgaria to Colorado. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • How long is the flight from Bulgaria to Colorado?

    United Airlines and Lufthansa can get you from Bulgaria to Colorado in just under 16h 30m. Your travel time can differ by up to 2h 30m. There are 5871 mi between Bulgaria and Colorado. Both multi-stop and nonstop flights can be found to your destination and back.

  • Can I find deals for flights from Bulgaria to Colorado that include hotel bookings?

    Yes. In addition to deals on Bulgaria to Colorado flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Bulgaria to Colorado?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Bulgaria to Colorado.

  • Can I find deals for business class flights from Bulgaria to Colorado?

    Yes. Cheapflights offers flight deals from Bulgaria to Colorado by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Bulgaria to Colorado?

    Currently, December is the cheapest month in which you can book a flight from Bulgaria to Colorado (average of $711). Flying from Bulgaria to Colorado in August is currently the most expensive (average of $834). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

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Top 3 airlines flying from Bulgaria to Colorado

Discover the top 3 airlines that operate flights from Bulgaria to Colorado. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated October 13, 2025.
AirlineCheapestAverageFlexibilityOn-time
Turkish AirlinesCheapest$704Average$803FlexibilityNo cancel feeOn-time77%
United AirlinesCheapest$729Average$781FlexibilityNo cancel feeOn-time69%
LufthansaCheapest$745Average$981FlexibilityNo cancel feeOn-time76%

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