United's Economy Plus offers up to 6 inches more legroom than standard economy seats.
Purchase Priority Boarding to secure overhead bin space, placing you in Zone 2.

Planning a trip from Denver to Dulles Intl? KAYAK’s data-powered insights will help you find cheap flights. Learn the best time to fly, how early to book your ticket, and other tips to secure great prices.
| Low season | January |
|---|---|
| High season | December |
| Cheapest flight | $69 |
Direct departures
Denver Intl to Washington, D.C. Dulles Intl
Monday
Southwest, United Airlines
Southwest, United Airlines
Tuesday
Southwest, United Airlines
Southwest, United Airlines
Wednesday
Southwest, United Airlines
Southwest, United Airlines
Thursday
Southwest, United Airlines
Southwest, United Airlines
Friday
Southwest, United Airlines
Southwest, United Airlines
Saturday
Southwest, United Airlines
Southwest, United Airlines
Sunday
Southwest, United Airlines
Southwest, United Airlines
Direct returns
Washington, D.C. Dulles Intl to Denver Intl
Monday
Southwest, United Airlines
Southwest, United Airlines
Tuesday
Southwest, United Airlines
Southwest, United Airlines
Wednesday
Southwest, United Airlines
Southwest, United Airlines
Thursday
Southwest, United Airlines
Southwest, United Airlines
Friday
Southwest, United Airlines
Southwest, United Airlines
Saturday
Southwest, United Airlines
Southwest, United Airlines
Sunday
Southwest, United Airlines
Southwest, United Airlines
Crew could have been friendlier, maybe I'm spoiled by SW crews. In flight wifi was good. Would be nice to have more food offerings on a 4 plus hour flight
Crew could have been friendlier, maybe I'm spoiled by SW crews. In flight wifi was good. Would be nice to have more food offerings on a 4 plus hour flight
Had to get off plane from prior flight even though I had to reboard same plane to continue to my final destination.
Everything a cheap airline should be at normal airline rates.
Plane crashed into a bus or some other vehicle on the ground while pulling out of the gate. No injuries, but wing tip was damaged and returned to gate for “maintenance issues” and we departed 5 hours later because the plane went out of service and new plane was flown in from a nearby airport, Midway.
Ever since Southwest starting charging for bags, passengers don't want to pay to check their bags, so the gate agents have to beg people to check their roller bags now because there's "not enough space". This was a terrible business move by Southwest.
Full cans of soda would be nice. A choice between two snacks would be appreciated.
Tried watching free movie and it kept freezing so I couldn’t finish.
All was good. I just had a hard time getting connected to the WiFi/internet during the flight
Sacrament staff are always polite and helpful. Airport is easy to maneuver and boarding is straightforward.
Great flight. Outstanding Service. Southwest was able to put us on a direct flight to Denver when the connection could have been affected by a later arrival to Baltimore. The direct flight was less expensive that the flight with the connection in Baltimore.
Great crew, excellent landing, good food. Over all great experience. Thank you!
One bag is incorrect and not acceptable for an international flight. The food was not just good. I won't fly with them again.
Not pleasant trip cross country when the entertainment and WiFi system not working. No entertainment for entirety of route. Staff was rather nonchalant in that they dismissed the problem due to age of plane. It would have been nice to know this up front so I could have come prepared to read or download movies before boarding Coincidentally or not, there was a similar issue with the entertainment system on my previous flight I took on my fist leg of the trip. There are no seat TVs, so you must rely on the app when it works. United can do better. Also, what use it it to pay for boarding group 2 when half of the passengers are in the same line as you?
Crew was dismissive. Snacks and refills not offered. Poor business class experience. Bed not comfortable compared to Emirates or BA.
Flight was delayed for 5 hours because crew didn’t have enough time to rest - this seems like it could have been avoided with better scheduling. Food was not good.
IAD with the archaic people movers is just a place to be avoided.
Overall, it was good. I was seating next to a wonderful lady and did not notice how time flew. Thanks
This is the best united airlines flight that I took. The crew was very friendly and the food was tasty!
It is clear that someone knew, and competent, is in charge of food at United Airlines at least for the international flights. I was flying in coach, but the choices of the dinner were excellent. Tasty, and appropriate size. I had the beef, which was a little bit like a shepherds pie, and it was good. Nothing comparable has been served on a United flight in years. It will not be confused with three star food, but it is very good for airline food. Even better was the breakfast choice between a cinnamon roll and a breakfast sandwich. I chose the breakfast sandwich which was absolutely delicious and which I would happily order again at my local Starbucks or Panera. It is clear that someone knew indifferent is in charge of the food and it’s about time.
Had one staff that was not pleasant. Seems they are stressed with too many people to care for.
When I wanted to check in 3 hours prior to boarding time, the employees mentioned “a little over an hour delay” so I waited for an hour then I went to go look for food in the terminal and most people from that flight were in the same area looking for food. Finally I decided after food to check to see if it’s anytime closer and now it’s 2 mins until boarding closes?! What are you kidding me? I didn’t receive anything via sms about boarding now nor via email or on the intercom. I luckily made it through, barely, and then there’s no room for my carry on mind you I’m in the very first row so I had to place my purse in one further row back and my carry on sections down. Not sure who pays for better seats to get your stuff placed all over the plane but that was the worst experience I’ve ever had flying with anyone.
Better than expected. Staff were friendly and nice on both flights.
There was no one at the counter to assist with our check in. The app didn’t work, so I arrived at the airport with time to check in and I couldn’t because no employees were there. When I finally got someone on the phone, it was inside the 60min rule and they said I could no longer check in and they could sell me another ticket. We had to scramble and pay an additional $800 for tickets and THEN AFTER (about 60 min from my original convo with customer service and 10min after original departure time) I had boarded my new flight, there was email saying my original flight from Frontier was delayed and leaving 2hr 50min later, but I STILL wouldn’t have been able to check in. Which means customer service should have been able to see it and let me check in because I was well within my check in time. When I call Frontier, they hang up on me. So their app didn’t work and they employees left and they take zero responsibility or assistance with their “customer service”
Terrible. Flight cancelled with no reasoning and no flights to rebook. Employees were useless and did nothing to help. Did not even know where to retrieve luggage from the cancelled flight. Flyers beware.
No fault of Frontier staff: plane was very late, reached Orlando at 1 am, took a while to get luggage. Weather, gov financial shutdown impact on TSA, air controllers seemed to have multiple flights backed up. Frontier staff seemed to cope as gracefully as possible. It did reassure me that I and my new hip could adapt to travel challenges. Food/entertainment were irrelevant to my trip.
Terrible. The canceled my entire flight when I requested a refund for a trip frontier canceled trip one way.
Boarding was on time and plane departed as scheduled. There are obviously no amenities (food, drink, entertainment) on Frontier, but there also didn't seem to be any issues with luggage space either.
Frontier is the Walmart of airlines. Frontier has removed adjustability and comfort from their seats to make the flight lighter and save gas. This makes it impossible to sleep on their flights. Their customer service is abysmal. Once, I bought a drink on the plane, and they swiped my credit card on the plane to pay for it. Then I got three weeks of daily notices from my bank telling me they tried to charge the wrong card number over and over again. I tried to call them, but they removed the ability to actually talk to someone that can resolve such a problem from their company to cut corners. The only way to talk to someone in person is to go to the check-in counter at the airport (40 minutes drive from my house). Eventually their system gave up on trying to charge the card, after 21 days of repeated tries. They don't pad their prices even a little to handle customer service issues like missed flights. They also have a blanket policy preventing helping you reschedule a missed flight if their system says you "cancelled" your own flight online. This is a major problem because their website is broken on mobile devices, the only web browser you have at the airport when their gate staff tell you that you have to reschedule your own missed flight online because they can't help you. I tried to reschedule my flight on my android device and instead, their website crashed and "cancelled" my missed flight. When I got to the counter, the agent argued with me for 5 minutes insisting that I intentionally cancelled my own flight (implying I had to buy another flight). She missed the point: the problem was that I could not buy another flight because their website is broken. I left to avoid more conflict with the "customer service" agent. I tried to redress my issue with their only other "customer service" chanel available: the contact form on their website. The response I got was more of the same: you cancelled your own flight, according to our website / computer records, therefore we won't help you. I was trying to explain the problem with their broken website that cost me hundreds of dollars by crashing / malfunctioning and resulting in a cancelled flight, but they only had deaf ears for this problem. Worst customer service I have ever experienced. I will never buy another Frontier flight again, because it is a risky, painful move that I will likely regret often.
What I expected, nickeled and dined and a frontier flight attendant loudly complained about her job and lack of communication as she headed to the gate on her cell phone. Not professional.
I’m not gonna fly Frontier Airlines because booking is not an option. No water or food is for high price, not equipped for health emergency incompetent crew for emergency services. Cheap airline shows it is cheaper in all service categories. Boarding is the best of all airlines!