Hi, as mentioned in a previous response it all depends on where you want to go. there is a useful download on the STAR ALLIANCE website that will work out if your route is valid and if also a price (the price does not include airport taxes etc) I have not used the download for a while so things may of changed

I have done 2 round the worlds although mine only lasted 3/4 weeks not the year or so that you are planning, my last RTW was for the following route

London-Singapore-Brisbane-Singapore-Hong Kong-Chicago-london

Flights were with singapore airlines & united Airlines cost was around £1100 this trip took place in 2005. If memory serves me correct Mileage is worked out in bands i.e.29000 miles, 35000 miles etc.

Hope the above is of some use

There isn't a simple answer to this question without knowing how many, and which, stops you want to make. Every arrival and departure attracts taxes and pushes the overall price up. Departing in July you will pay high season prices out of the UK and all airline tickets have a maximum validity if 12 months. If you want to go for longer overall, you may need to buy two tickets. If you have a look at the Star Alliance website you can develep a round the world itinerary, choosing between 3 and 15 stops which should give you an idea of what is possible but this is not something to booked on the web, you need to talk face to face or on the phone with an experienced travel agent to get the best deal

I'm looking for a round the world flight leaving this July, can be 12 or 18 months in lenght and needs to include Bangkok and Australia. How much should I pay including taxes?