United Flight 644 Deals & Information (2025/2026)

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United Flight 644 Route Deals From $213

The cheapest prices found with in the last 7 days for return flights were $289 and $213 for one-way flights to Pittsburgh Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Wed, Sep 10 - Sun, Sep 14
SFO
San Francisco Intl.
PIT
Pittsburgh Intl.
$289 Roundtrip, found 2 days ago
$289
Roundtrip
found 2 days ago
Select United flight, departing Wed, Sep 10 from San Francisco Intl. to Pittsburgh Intl., returning Sun, Sep 14, priced at $289 found 2 days ago
Wed, Aug 6 - Thu, Aug 14
SFO
San Francisco Intl.
PIT
Pittsburgh Intl.
$295 Roundtrip, found 5 days ago
$295
Roundtrip
found 5 days ago
Select United flight, departing Wed, Aug 6 from San Francisco Intl. to Pittsburgh Intl., returning Thu, Aug 14, priced at $295 found 5 days ago
Wed, Sep 10 - Sun, Sep 14
SFO
San Francisco Intl.
PIT
Pittsburgh Intl.
$299 Roundtrip, found 2 days ago
$299
Roundtrip
found 2 days ago
Select United flight, departing Wed, Sep 10 from San Francisco Intl. to Pittsburgh Intl., returning Sun, Sep 14, priced at $299 found 2 days ago
Fri, Jul 11 - Mon, Jul 14
SFO
San Francisco Intl.
PIT
Pittsburgh Intl.
$304 Roundtrip, found 22 hours ago
$304
Roundtrip
found 22 hours ago
Select United flight, departing Fri, Jul 11 from San Francisco Intl. to Pittsburgh Intl., returning Mon, Jul 14, priced at $304 found 22 hours ago

Frequently asked questions

What route does flight number UA644 take?
UA644 serves multiple routes, but the most common is between Austin, TX Airport (AUS-Austin-Bergstrom Intl.) and Denver, CO Airport (DEN-Denver Intl.). If your flight goes direct, you'll stroll through arrivals in roughly 2 hours and 12 minutes. Multi-stop flights can also travel under the same number, as can flights on other routes.
What kind of plane is on flight number UA644?
There's a strong chance you'll be heading off on a Boeing 737-800 if you're going from AUS to Denver, CO Airport (DEN-Denver Intl.), one of several routes used for flight number UA644.
If I am not able to travel due to COVID-19, can I change my flight to a later date?
For more info about changing your UA644 flight with Travelocity, please visit our Customer Service Portal.