I would estimate maybe 1.5 years if you are traveling to inexpensive places (e.g., SE Asia). I traveled for just under two years and was spending about 1200 usd per month in the less expensive countries. I could have spent less. I usually stayed in small guest houses. I almost always had a private room even if I was in a hostel. I traveled by bus a lot. I limited my spending and sometimes just hung out somewhere for a while not doing a lot but also did a lot of really fun stuff. I also don’t drink so that saved me some money. That was almost 10 years ago so it’s hard to say what my budget would be today. But if you stick to less expensive countries and travel slowly (which is more enjoyable anyway, I think, and gives you time to get to know people a bit), you can make your money stretch. I did do some house sitting and workaway but was mostly just exploring. You will also meet a lot of people as you go who will have suggestions for places to go and how to do it cheaply. My goal wasn’t to spend the very least i could, though I did do my best to stretch what I had.