Err yes it depends on region lol. Poor SEA countries you can easilly get by on 10GBP per day (low budget) (Malaysia, Thailand, Laos, Cambodia, Vietnam & the likes). India is easy on 10 GBP aswell, you could survive on less. China I BELIEVE (atleast this is my budget for when I go there.. but I wont know till I get there) you can survive on 10-15GBP per day. Hong kong is a lot more expensive, your looking at 20GBP ish, but skys the limit there (you could probably survive on less than this, but its about what I spent there). Singapore is similar budget to Hong Kong
This includes train/bus travel, accommodation, tourist entree fees, and food. If you want to do expensive activities or fly on planes it will be much more expensive. Reserve that till your earning money :P