Is $20 a day realistic for the whole country?

It is very tight. While easy in the North, costs are slightly higher in the South and in major tourist hubs like Hoi An. You will need to balance cheaper days with slightly more expensive ones.

How do I handle money?

Use a bank card that refunds ATM fees, as local ATMs charge per withdrawal. Withdraw large amounts at once to minimize these fees.

Vietnam on $20 a day: A survival guide

To survive on $20 a day in Vietnam, you must prioritize street food, stay in hostel dorms, and utilize public buses or trains over domestic flights. Stick to local markets and avoid alcohol to keep your daily spending within this tight limit.

Sleep in dorms. Book hostel dorm beds in cities like Hanoi or Da Nang, which typically cost $5–$7 per night. Use sites like Hostelworld but contact the property directly to see if you can get a better rate for a weekly stay.
Eat exclusively street food. Avoid sit-down restaurants. A bowl of pho or a Banh Mi from a street stall will cost you $1.50–$2.00. Eat two meals a day at these stalls and keep snacks limited to local fruit.
Master the public bus. In major cities, use local buses (often $0.25 per ride) rather than Grab or taxis. For inter-city travel, take the 'sleeper' bus or the slow train; book these at least 48 hours in advance to secure the cheapest seat.
Cut the beer. Alcohol is the budget killer. A single beer in a bar can eat 10-15% of your daily budget. Drink 'Bia Hoi' (fresh beer) if you must, which costs about $0.50, but generally stick to bottled water or free tea provided at hostels.

Is $20 a day realistic for the whole country?: It is very tight. While easy in the North, costs are slightly higher in the South and in major tourist hubs like Hoi An. You will need to balance cheaper days with slightly more expensive ones.
How do I handle money?: Use a bank card that refunds ATM fees, as local ATMs charge per withdrawal. Withdraw large amounts at once to minimize these fees.