Tampa International Airport United Airlines
Photograph ©2015 by Brian Cohen.

United Airlines Pi Day Sale 2021: One Way Flights Start at $31.40 or 3,140 MileagePlus Miles

In celebration of Pi Day, United Airlines launched its Pi Day sale for this year — through which the cost of one way flights within the United States starts at either $31.40; or 3,140 MileagePlus miles plus taxes and fees which start at $5.60 — for travel between Sunday, March 28, 2021 and Saturday, June 5, 2021…

United Airlines Pi Day Sale 2021: One Way Flights Start at $31.40 or 3,140 MileagePlus Miles

…but you must book your tickets for your flights by the end of today, Monday, March 15, 2021 in order to take advantage of this sale.

The reason why March 14 is Pi Day is because it is also known numerically as 3-14 or 3/14 or 3.14; so Pi Day was yesterday, Sunday, March 14, 2021. Pi — which is also known by the Greek letter π — is the ratio of the circumference of any circle to the diameter of that circle, a mathematical constant, an irrational number, and a transcendental number. It is approximately equivalent to 3.14159265358979323846264338327950288419716939937510… — the decimal representation of the number never ends — and usually is shortened to simply the more popular 3.14.

At least 73 flights are on sale for either $31.40; or 3,140 MileagePlus Miles plus taxes and fees which start at $5.60 — they are listed below after the conclusion of this article — but many more flights are on sale from $49.00 to $139.00; or from 5,500 MileagePlus miles to 12,500 MileagePlus miles.

Select Terms and Conditions

Tickets must be purchased at least 14 days prior to departure, but no later than March 15, 2021. Roundtrip purchase is not required.

Fares shown are valid for travel on Monday, Tuesday, Wednesday and Thursday. Fares are valid in the Economy (Coach) cabin on United/United Express carriers and certain codeshare operated flights only. Some flights may be operated by the following airlines, doing business as United Express: Air Wisconsin, CommutAir, ExpressJet Airlines, GoJet Airlines, Mesa Air, Republic Airlines, or SkyWest Airlines; or may be operated pursuant to a codeshare agreement, such as Silver Airways.

No minimum stay is required.

Travel is valid for any day meeting travel period requirements, so blackout dates do not apply.

Fares, fees, rules and offers are subject to change without notice. Seats are capacity-controlled and may not be available on all flights or days. Fares are nonrefundable except during the first 24 hours after purchase. Other restrictions may apply.

Award Tickets: Passenger is responsible for all taxes, fees, baggage fees and surcharges applicable to award travel, including, with respect to government imposed taxes and fees, September 11th Security Fee of $5.60 per one-way trip that does not include a government defined stopover, US Customs, Immigration and APHIS User Fees of $16.95 for each international arrival in the U.S.; and non-U.S. government ticket taxes, fees and airport charges may add up to $300 per ticket as of January 1, 2021. Such taxes, fees and surcharges must be paid at the time of ticketing and are subject to change. Any valid unused award ticket may be returned to the MileagePlus Service Center, for a service charge, up to one year from the date of issue. Award seats are subject to availability and capacity-control restrictions apply.

Fares listed are Basic Economy tickets which are subject to additional restrictions including, but not limited to: no seat selection, no group or family seating, no full-sized carry-on bags and no flight changes or refunds except as stated in the United 24-hour flexible booking policy. Advance seat assignments may be available for purchase during booking and up until check-in opens. You’ll be eligible to purchase Economy Plus® seating at check-in only. Certain MileagePlus® and MileagePlus Premier® member benefits are not available.

Additional charges may apply for checked baggage and other additional options. Fares, mileage levels, fees, rules and offers are subject to change without notice. Fares are capacity-controlled and may not be available on all flights or days.

Fares listed are per person and include government taxes and fees. Some restrictions may apply. Fares do not include applicable charges for baggage or optional services.

Other restrictions, term, and conditions may apply.


Keep in mind that all tickets which are currently sold — including those for Basic Economy — are not subject to change fees. At the time this article was written, Basic Economy tickets will no longer be changeable after Wednesday, March 31, 2021 — unless the waiver is extended further into the future by United Airlines. If you can do without selecting your seats instead of having them selected for you, guaranteed group or family seating, and full-sized items to carry aboard the airplane, then Basic Economy tickets are ideal for you.

Photograph ©2015 by Brian Cohen.

The 73 one way flights within the United States which start at either $31.40 or 3,140 MileagePlus miles — plus taxes and fees which start at $5.60 — include:

  1. Albuquerque (ABQ) – Denver (DEN)
  2. Albany (ALB) – Washington, D.C. (IAD)
  3. Austin (AUS) – Houston (IAH)
  4. Hartford (BDL) – Washington, D.C. (IAD)
  5. Nashville (BNA) – Chicago (ORD)
  6. Boston (BOS) – New York/Newark (EWR)
  7. Boston (BOS) – Washington, D.C. (IAD)
  8. Buffalo (BUF) – Chicago (ORD)
  9. Buffalo (BUF) – Washington, D.C. (IAD)
  10. Burbank (BUR) – San Francisco (SFO)
  11. Charleston (CHS) – Washington, D.C. (IAD)
  12. Cleveland (CLE) – New York/Newark (EWR)
  13. Cleveland (CLE) – Chicago (ORD)
  14. Cleveland (CLE) – Washington, D.C. (IAD)
  15. Charlotte (CLT) – Washington, D.C. (IAD)
  16. Columbus (CMH) – Chicago (ORD)
  17. Columbus (CMH) – Washington, D.C. (IAD)
  18. Colorado Springs (COS) – Denver (DEN)
  19. Corpus Christi (CRP) – Houston (IAH)
  20. Cincinnati (CVG) – Chicago (ORD)
  21. Cincinnati (CVG) – Washington, D.C. (IAD)
  22. Denver (DEN) – Wichita (ICT)
  23. Denver (DEN) – Omaha (OMA)
  24. Denver (DEN) – Salt Lake City (SLC)
  25. Denver (DEN) – Oklahoma City (OKC)
  26. Dallas (DFW) – Houston (IAH)
  27. Detroit (DTW) – Washington, D.C. (IAD)
  28. Detroit (DTW) – Chicago (ORD)
  29. New York/Newark (EWR) – Pittsburgh (PIT)
  30. New York/Newark (EWR) – Portland, ME (PWM)
  31. New York/Newark (EWR) – Raleigh (RDU)
  32. Fresno (FAT) – Los Angeles (LAX)
  33. Flint (FNT) – Chicago (ORD)
  34. Killeen (GRK) – Houston (IAH)
  35. Grand Rapids (GRR) – Chicago (ORD)
  36. Greenville (GSP) – Washington, D.C. (IAD)
  37. Harlingen (HRL) – Houston (IAH)
  38. Washington, D.C. (IAD) – Raleigh (RDU)
  39. Washington, D.C. (IAD) – Louisville (SDF)
  40. Washington, D.C. (IAD) – New York (LGA)
  41. Washington, D.C. (IAD) – Norfolk (ORF)
  42. Washington, D.C. (IAD) – Rochester (ROC)
  43. Washington, D.C. (IAD) – Manchester (MHT)
  44. Washington, D.C. (IAD) – Ithaca (ITH)
  45. Washington, D.C. (IAD) – Providence (PVD)
  46. Washington, D.C. (IAD) – Pittsburgh (PIT)
  47. Houston (IAH) – Tulsa (TUL)
  48. Houston (IAH) – Little Rock (LIT)
  49. Houston (IAH) – Mcallen (MFE)
  50. Houston (IAH) – Oklahoma City (OKC)
  51. Houston (IAH) – San Antonio (SAT)
  52. Houston (IAH) – Pensacola (PNS)
  53. Houston (IAH) – New Orleans (MSY)
  54. Houston (IAH) – Midland (MAF)
  55. Houston (IAH) – Memphis (MEM)
  56. Las Vegas (LAS) – Los Angeles (LAX)
  57. Las Vegas (LAS) – San Francisco (SFO)
  58. Los Angeles (LAX) – San Francisco (SFO)
  59. Los Angeles (LAX) – Phoenix (PHX)
  60. Los Angeles (LAX) – Sacramento (SMF)
  61. Los Angeles (LAX) – Reno (RNO)
  62. Los Angeles (LAX) – Palm Springs (PSP)
  63. Kansas City (MCI) – Chicago (ORD)
  64. Memphis (MEM) – Chicago (ORD)
  65. Minneapolis (MSP) – Chicago (ORD)
  66. Omaha (OMA) – Chicago (ORD)
  67. Chicago (ORD) – Saint Louis (STL)
  68. Chicago (ORD) – Pittsburgh (PIT)
  69. Chicago (ORD) – Louisville (SDF)
  70. Redmond (RDM) – San Francisco (SFO)
  71. Reno (RNO) – San Francisco (SFO)
  72. San Diego (SAN) – San Francisco (SFO)
  73. San Francisco (SFO) – Orange County (SNA)

Subscribe To Our Newsletter

Join our mailing list to receive the latest news and updates from our team.

You have Successfully Subscribed!