Southeast AsiaUpdated July 1, 20263–4 weeksTransport: $180–350
Cheapest Flights to Southeast Asia: The Ultimate Thailand–Vietnam–Cambodia Backpacking Loop
I did this loop with a 38L pack and a hard rule: nothing over $50 unless it saved me an entire day. The one time I broke it — a last-minute Siem Reap to Bangkok flight at $118 — still stings more than the 8-hour bus I was avoiding. Here's exactly what each leg costs when you book it properly, and where the buses beat the planes.
Route Overview
Bangkok → Chiang Mai → Hanoi → Ha Long Bay → Hoi An → Ho Chi Minh → Siem Reap → Bangkok
1.Bangkok → Chiang Mai
$25–$451h 15m flight
Thai AirAsia, Nok Air and Thai VietJet all fly this hourly. Book 2–3 weeks out. The overnight sleeper train from Krung Thep Aphiwat station ($18–30, 13h) is the romantic alternative — book the lower bunk a week ahead.
Search Bangkok → Chiang Mai flights2.Chiang Mai → Hanoi
$55–$1101h 40m flight
Thai AirAsia flies direct several times a week — book 4–6 weeks out for the $55–70 fares. The overland alternative (slow boat Chiang Rai → Luang Prabang, then a brutal 24h bus to Hanoi) takes 3+ days and only saves about $30.
Search Chiang Mai → Hanoi flights3.Hanoi → Ha Long Bay
$10–$152.5–4h shuttle
No flight needed — every hostel books a shuttle bus to Ha Long City or Cat Ba for $10–15. For the bay itself, a 1-night cruise starts around $60; the Cat Ba route (kayak day trip, ~$25) is the budget move.
Search Hanoi → Ha Long Bay flights4.Ha Long Bay → Hoi An
$30–$601h 20m flight
Return to Hanoi, then VietJet or Bamboo Airways to Da Nang (30 min by taxi from Hoi An). Book 2–4 weeks out. The overnight sleeper train Hanoi → Da Nang ($28–40, 16h) saves a hostel night and the Hai Van Pass views at dawn are legitimately great.
Search Ha Long Bay → Hoi An flights5.Hoi An → Ho Chi Minh City
$25–$551h 20m flight
VietJet flash sales drop this to $25 almost every Tuesday. Book 2–3 weeks out and fly from Da Nang, 45 minutes from Hoi An by $2 public bus. The train version is 17+ hours — only worth it if you stop in Nha Trang on the way.
Search Hoi An → Ho Chi Minh City flights6.Ho Chi Minh City → Siem Reap
$18–$2810–13h bus
Giant Ibis and Mekong Express run direct buses ($18–28) with border assistance at Moc Bai. Flying costs $70–130 and only saves half a day — take the bus and spend the difference on Angkor Wat's 3-day pass ($62).
Search Ho Chi Minh City → Siem Reap flights7.Siem Reap → Bangkok
$15–$258–10h bus
The direct Nattakan bus ($25) crosses at Poipet without forcing you off at a 'visa agency.' Ignore anyone who says you need a Thai visa before the border — you don't. Flying direct costs $60–120; book 4+ weeks out if you must.
Search Siem Reap → Bangkok flights
Cost Breakdown
All prices in USD, researched estimates updated quarterly. Your mileage (and exchange rate) may vary.
| Category | Estimate | Notes |
|---|---|---|
| Long-haul flight into Bangkok (BKK) | $450–750 return | From the US West Coast via Taipei or Manila; from Europe via the Gulf carriers. Cheapest months: September and late January. |
| Flights within the loop (4 legs) | $135–270 | BKK→CNX, CNX→HAN, HAN→DAD, DAD→SGN booked 2–6 weeks out on budget carriers, carry-on only. |
| Overland legs (bus + train) | $45–80 | Ha Long shuttle, HCMC→Siem Reap, Siem Reap→Bangkok. Swap any flight for an overnight train to shave another $60–100. |
| Visas | $55–61 | Vietnam e-visa $25 (apply at the official .gov.vn site only), Cambodia visa on arrival $30 + $6 'processing' at land borders. Thailand is visa-free for most passports. |
| Checked-bag fees (the silent killer) | $0–120 | Every budget carrier on this route charges $20–40 per checked bag per leg. Travel carry-on only and this line is zero. |
| Total transport | $235–410 | Flying the four long legs and bussing the rest. A full-overland version gets under $200 but costs you ~4 travel days. |
Best Booking Strategy
Book the long-haul into Bangkok 2–4 months out, targeting Tuesday or Wednesday departures. Bangkok (BKK) and Kuala Lumpur (KUL) are almost always the cheapest entry points into the region — if KUL is $100+ cheaper, grab it and buy a separate $30 AirAsia hop to Bangkok.
Book regional budget flights 3–6 weeks out, never inside the final week — Thai AirAsia and VietJet fares roughly double in the last 7 days. Set price alerts on the Chiang Mai → Hanoi and Da Nang → HCMC legs; they're the two with real volatility.
Carry-on only is non-negotiable. Four budget flights at $25–40 per checked bag adds $100–160 to a $150 flight budget. A 38–40L pack under 7kg passes every airline on this route.
Use overnight transport as accommodation. The Bangkok → Chiang Mai sleeper train and the Hanoi → Da Nang train each replace a hostel night ($8–15), which effectively makes them cheaper than the flight they replace.
Related Stamps
Been on this route? Claim the on-chain stamp for every country you crossed.
FAQ
What's the best time of year to do this loop?
November to February: dry season in all three countries, and the only time Ha Long Bay isn't grey. It's also peak season, so book regional flights 5–6 weeks out instead of 3. September–October is the budget sweet spot — some rain, far fewer tourists, and the cheapest fares of the year.
Should I buy a multi-city ticket or separate one-ways?
Separate one-ways on budget carriers, almost always. A traditional multi-city ticket on full-service airlines prices this route at $600+; piecing it together on AirAsia and VietJet comes in under $270. The only exception is your long-haul: an open-jaw into Bangkok and out of Singapore (or vice versa) can beat a return ticket.
Do I need to arrange visas before I go?
Vietnam: yes — the e-visa takes 3–5 working days via the official immigration site ($25). Cambodia: no — visa on arrival at airports and land borders ($30). Thailand: most Western passports get 60 days visa-exempt. Get all visas yourself; border 'helpers' selling express visas are running a markup scam.
How long do I need for the full loop?
Three weeks is brisk but doable; four is comfortable. The classic split is 4 days Bangkok, 3 Chiang Mai, 2 Hanoi, 1–2 Ha Long, 3 Hoi An, 2 HCMC, 3 Siem Reap, with 4–5 travel days between. Under two weeks, drop either Chiang Mai or Ha Long Bay — don't just compress everything.
Is it safe to take overnight buses and trains?
Yes, with standard precautions: keep your daypack (passport, cash, electronics) on your body or as a pillow, never in the luggage hold or overhead rack. The Vietnamese sleeper trains are safer than the overnight buses in Cambodia, where bag-dipping from the hold is a known problem — valuables stay in the cabin with you.
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