Should I carry a lot of cash?

No. Carry enough for 3 days of expenses. Use ATMs to pull out local currency as needed. Never keep your entire budget in one place.

How much does a 'chaos fund' need to be?

$500 is the minimum. It covers one emergency medical visit, a last-minute flight change, or a replacement laptop if yours breaks.

How to budget for long-term travel in Southeast Asia

Budget for $40–$60 USD per day to cover comfortable mid-range accommodation, street food, and regional transport. Keep an extra $500 as a 'chaos fund' in a separate high-yield savings account for emergencies, flights home, or sudden gear failure.

Establish your daily burn rate. Track your spending for the first 7 days. In SE Asia, your baseline should be $30 for bare-bones backpacking or $60 for a more comfortable 'flashpacker' lifestyle including private rooms and daily massages.
Separate your 'sunk' costs. Pre-calculate your non-negotiables: travel insurance ($60/mo), visa fees (budget $30 per country entry), and your flight to the region. These don't come out of your daily spending money.
Use the 'ATM Shuffle' for fees. Avoid bank fees by using a card that reimburses ATM charges (like Charles Schwab) and always decline the bank's 'Dynamic Currency Conversion' on screen—choose to be charged in the local currency to get a better exchange rate.
Automate your savings replenishment. Set up a recurring transfer from your main account to your travel debit card every Monday. This prevents you from overspending your weekly allotment early in the trip.

Should I carry a lot of cash?: No. Carry enough for 3 days of expenses. Use ATMs to pull out local currency as needed. Never keep your entire budget in one place.
How much does a 'chaos fund' need to be?: $500 is the minimum. It covers one emergency medical visit, a last-minute flight change, or a replacement laptop if yours breaks.