The cheapest domestic flight in the US right now is $46 — Phoenix to LA on Frontier. Fort Lauderdale has the lowest average roundtrip fare of any domestic destination at $95. But “cheapest” means nothing if you end up paying $65 in bag fees on top of a $49 ticket.
We tracked domestic flight prices for six months across Google Flights, Southwest.com, and Going.com. Here's how to actually get cheap flights — including the hidden costs nobody mentions upfront.
At a Glance
Cheapest Fare Found
$46 one-way (PHX→LAX, Frontier)
Cheapest Destination (Avg RT)
Fort Lauderdale — $95
Best Booking Window
1–3 months ahead
Biggest Hidden Cost
Carry-on bag fees on ULCCs ($35–65)
Best All-In Value
Southwest (2 free checked bags)
Prices Checked
March 28, 2026
The Airline Tier System — Know What You're Buying
Not all cheap tickets are created equal. The US airline market splits into three tiers, and understanding them is the difference between a $49 fare that costs $150 and a $89 fare that's actually $89.
Full-Service: Delta, United, American, Alaska, JetBlue
Higher base fares but the ticket includes overhead bin access, free changes (on most fare types), and sometimes meals on longer routes. Delta and United have built loyalty programs that accrue genuine long-term value — if you fly 20+ segments per year, the status perks (upgrades, lounge access, waived fees) add up to hundreds in savings.
Best for: business travelers, anyone checking bags, connections through major hubs.
Low-Cost: Southwest, Breeze, Avelo
Southwest is in a category of its own: two free checked bags, no change fees, no cancellation fees, open seating. For a family of four flying roundtrip, the bag savings alone total $120–240 compared to Delta or United. Breeze and Avelo are newer airlines flying point-to-point on underserved routes — limited networks but genuinely cheap when they serve your city pair.
Best for: flexible leisure travelers, families (Southwest bag savings are massive).
Ultra-Low-Cost (ULCC): Spirit, Frontier, Allegiant
Base fares from $29–49, but bags, seat selection, and even water cost extra. The “real” price after add-ons is typically 60–100% higher than the advertised fare. Frontier is the cheapest option in 15 states by price-per-mile. Allegiant flies to secondary airports — Phoenix-Mesa instead of Phoenix Sky Harbor, which adds 45 minutes and an Uber to your trip. Spirit has the most complaints per passenger of any US airline.
Best for: solo travelers with a backpack who understand the model and avoid every add-on.
The 7 Strategies That Actually Lower Your Fare
1. Use Google Flights' Date Grid
Google Flights shows the lowest fare for every day of the month in a single view. Flexible dates save 30–50% on the same route — a Tuesday departure might cost $89 when Friday costs $220. Use the “Date grid” or “Price graph” view, enable “Flexible dates,” and check “Nearby airports” for your metro area. This single tool does more for finding cheap flights than anything else.
2. Set Price Alerts (Not “Check on Tuesdays”)
The “book on Tuesday at 3 PM” advice has a grain of truth but isn't reliable enough to matter. What actually works: set price alerts on Google Flights for your route and dates. You'll get an email when prices drop. Hopper and Going.com (formerly Scott's Cheap Flights) do the same thing with more sophistication. Let the algorithm watch prices for you — checking manually is a waste of your time.
3. Know the Booking Sweet Spot
For domestic flights, the pricing sweet spot is 1–3 months before departure. Last-minute domestic fares have gotten significantly more expensive since 2023 as airlines learned they can charge business travelers premium prices. Booking 6+ months out means you're paying for certainty, not value. The exception: Southwest sometimes drops fares 2–3 weeks out to fill planes — their Low Fare Calendar catches these.
4. Consider Secondary Airports
The savings can be $50–200 per ticket, but factor in ground transport time and cost:
- New York: EWR vs JFK vs LGA — or Stewart (SWF) and Islip (ISP) for ULCCs
- Los Angeles: LAX vs Burbank (BUR) vs Long Beach (LGB) vs Ontario (ONT)
- Chicago: O'Hare (ORD) vs Midway (MDW) — Midway is a Southwest hub and often cheaper
- Bay Area: SFO vs Oakland (OAK) vs San Jose (SJC)
A $60 savings on a flight evaporates if the secondary airport adds a $40 Uber and an extra hour of travel. Do the math for your specific situation.
5. Stack Deals: Credit Card Points + Sale Fares
The real value of travel credit cards isn't the points — it's transferring those points to airline partners at favorable rates:
- Chase Sapphire Preferred/Reserve: 5x on travel through Chase Travel portal. Points transfer 1:1 to Southwest, United, JetBlue, and others.
- Capital One Venture: 2x on everything, easy $0.01/point redemption, or transfer to partners.
- Amex Gold: 3x on flights booked directly with airlines. Transfer to Delta at 1:1.
Never use points at face value through generic portals. Transferring to airlines gets you 50–100% more value per point.
6. Join Going.com (Formerly Scott's Cheap Flights)
The free tier catches some deals. Premium ($49/year) catches most, including mistake fares and targeted sales from your home airport. One deal typically pays for the annual membership. Worth it if you fly three or more times per year and have flexible travel dates.
7. The Southwest Fare Calendar Trick
Southwest doesn't show up on Google Flights, Kayak, or most third-party search engines. You have to check Southwest.com directly. Their “Low Fare Calendar” displays the cheapest fare for each day of the month — and Southwest fares are often competitive with ULCC fares while including two free checked bags and no change fees. For a family of four, Southwest is almost always cheaper all-in than Spirit or Frontier.
Cheapest Domestic Destinations in 2026
| Destination | Avg RT Fare | Best Months | Cheapest From |
|---|---|---|---|
| Fort Lauderdale, FL | $95 | Jan, Sep | Major hubs nationwide |
| Orlando, FL | $110 | May, Sep | Nationwide (competition drives fares down) |
| Chicago, IL | $115 | Apr–May, Sep–Oct | East Coast hubs |
| Denver, CO | $120 | Shoulder months | Midwest and East Coast |
| Las Vegas, NV | $125 | Tue–Thu travel | West Coast hubs |
| New Orleans, LA | $115 | Jan–Mar, Oct | Southeast hubs |
| Austin, TX | $130 | Sep–Nov | South and Midwest |
Average roundtrip fares from Skyscanner and Google Flights data, March 2026. Fares from specific cities will vary.
The Hidden Cost Calculator
This is where the math exposes the ULCC model. A $49 Spirit ticket vs an $89 Southwest ticket — which is cheaper? Depends on what you bring:
| Fee | Spirit ($49 base) | Southwest ($89 base) | Delta ($129 base) |
|---|---|---|---|
| Carry-on bag | +$39 | Free | Free |
| Checked bag | +$35 | Free (x2) | +$35 |
| Seat selection | +$10 | Free (open seating) | +$0 (basic) |
| Change fee | $0–99 | Free | $0 (most fares) |
| Real Cost (1 checked bag) | $133–232 | $89 | $164 |
The Punchline
Southwest at $89 is cheaper than Spirit at $49 for anyone checking a bag. The only scenario where ULCCs win: you're flying solo with a personal item (small backpack) and you don't care about seat selection or changes. For everyone else, compare the all-in cost, not the headline fare.