It depends a lot on what type of traveller you are and how much travelling you plan to do.
With a couple of exceptions (notably Ko Phi Phi and some parts of Phuket) you should be able to get a basic fan-cooled room for under 300 baht. If you want air-con then you're looking at ther 500-1,000B range. Facilities like swimming pools, business centres and again push the price upwards. Take a look through the various accommodation sections on Travelfish to get an idea of what standard of accommodation works for you.
If you're eating on the street, three meals a day, then 100-150B per day is adequate. If you're eating three staple meals in a backpacker style restaurant, you'll be spending more like 250-400B a day. If you're eating dinner at proper restaurants, then you could easily be spending 300B or more a meal.
Thailand is hot and you'll need to be drinking a lot of water. At least two to three litres of water a day -- that will cost around 40-60B a day.
Booze is generally cheap compared to what you'd pay at home. A large bottle of beer can cost around 50B, a bottle of good gin or vodka around 600B. If you've having a couple of big beers every night with dinner, this will add up quickly.
Buses, trains and low cost flights are all very affordable. There is no real guideline in this regard as it depends entirely on how far and frequently you are travelling.
Ways to spend less
The following stories on Travelfish may be useful:
Ten ways to save money while travelling
How to manage your money while travelling in Asia
What does it cost to travel in Asia? Costs you face before departure
Please find below some of the more frequently asked questions (FAQ) people have about travelling to Thailand. We've tried to answer all the most frequently asked questions, but if you have another query about Thailand, please try our Travelfish messageboard.
Is it possible to rent rooms or dormitories for long periods of time?
Rooms: is a fan room ok, or should I budget for air-con?
Should I take my own padlock for the door of my room while travelling in Thailand?
What should I do if a bag is stolen from my room or dormitory while travelling in Thailand?
What standard of acommodation can I expect for US$5?
Why are there so few dormitories in Thailand?
Can I drink the tap water in Thailand?
How can I avoid MSG in Thailand?
How do I avoid peanuts in Thailand?
I have a food allergy - will I cope?
Is there good vegetarian food in Thailand?
Is western food available in Thailand?
Are the ferries in Thailand safe?
Are the trains in Thailand safe?
Do they trains run on time?
Is it easy to hitch-hike in Thailand?
Is it easy to rent a car or motorcycle in Thailand?
Should I get a tourist minibus in Thailand?
What is Bangkok's bus system like?
Which is the better way to travel around Thailand - train or bus?
Are credit cards accepted in Thailand?
Are there ATMs in Thailand?
How can I have money sent to me in Thailand?
How can I send money out of Thailand?
Should I bring travellers cheques, credit/debit cards or cash to Thailand?
Should I tip in Thailand?
Are leeches a problem in Thailand?
Are legal drugs cheap in Thailand?
Do I need a prescription in Thailand?
Do I need malarial medication in Thailand?
General food and water precautions in Thailand
General health advice for Thailand
HIV/AIDS in Thailand
Is cholera a problem?
Is heatstroke a problem in Thailand?
Is medical care cheap in Thailand?
Is medical care in Thailand good?
Is rabies a problem in Thailand?
Schistosomiasis in Thailand?
Traveller's medical kit for travel in Thailand
What about dengue fever in Thailand?
Will I get diarrhoea in Thailand?
Are there many internet cafes in Thailand?
Can I travel with a laptop in Thailand?
Is there ADSL internet access in Thailand?
What is mobile phone coverage like in Thailand?
What is the voltage in Thailand?