Many tourists choose to stay at Khao San Road, and many of them want to visit Chatuchak Weekend Market. Actually, the market is just 5-minute walk from BTS Skytrain (Mo Chit Station) and MRT Subway (Chatuchak Park Station). But unfortunately Khao San Road does not connect with BTS Skytrain nor MRT Subway!
Here are the options to get from Khao San Road to Chatuchak Weekend Market.
Ferry + BTS
With this option, first of all you have to walk to the Phra Arthit Pier. Then take the Chao Phraya Express Boat to Sathorn Pier (or Central Pier) (around 15 baht). Sathorn Pier connects to the BTS Skytrain at Saphan Taksin Station, so you can take BTS Skytrain from there to Mo Chit Station, which is the terminal station (around 42 baht). After getting off from the BTS skytrain, you will see many people walk to Chatuchak Weekend Market. This is not the shortest way, but you do not have to face the traffic jam in Bangkok, and it takes around 50 minutes to reach the market.
This is of course the easiest option. The distance between Khao San Road and Chatuchak Market is around 10 kilometers, so the taxi fare should be around 100 baht. Well, it can cost more depending on the traffic. This option is more expensive than the first options if you travel alone. But if you travel with friends, it could be cheaper!
Taxi + MRT
With this option, from Khao San Road, you take taxi to MRT Subway at Hua Lamphong Station (around 60 baht). Then, take MRT Subway to Chatuchak Weekend Market (around 42 baht). If you come by MRT Subway, instead of getting off at Chatuchak Park, I recommend you to get off at Kampheng Phet because it will lead you into the middle of the market. Personally, I do not recommend this option because it is not cheap and you also have to face traffic jam while riding taxi to the subway!
Bus is the cheapest way to reach the market. You can take bus number 524 and number 3 from Khao San Area (ask the local for the bus stop), the fare is less than 20 baht or if you are lucky, you might meet ‘free bus’. It can take only half an hour or up to more than an hour to reach the market depending on the traffic. In Bangkok, the bus has no schedule, so you have to wait until it comes. The waiting time could be only one minute or more than 30 minutes.
If you do not know Thai and also not know the way, I do not recommend this option. You should be aware that most drivers and collectors do not speak English and the sign around the bus is written in Thai only.
So, just choose the one that fits you. Enjoy traveling!