How much will i need?

ok my flights are apid for and deposits on my hotels are paid for.

just really want to know roughly how much money i should take with me. im staying in japan for 17 nights. by the time it comes for my trip i should have roughly £1000 saved which is about 211,393 Japanese yen.

i dont really indend on doing many expensive things maybe a trip to disney and USJ.

do you think what i will have saved will be enough or will i need any more?

I assume you are staying around Tokyo all the time. So, transportation costs will likely be under 1000 yen per day.

The following page gives information on food and other expenses:
http://www.japan-guide.com/e/e2410.html

And the following section lists admission fees for major tourist attractions:
http://www.japan-guide.com/e/e2164.html

Matthew I usually allow Y7000-Y8000 a day for food and sightseeing costs. That gets me reasonable meals, a few fares and an entry fee here and there.
Your issue is, how much are your hotels going to cost on top of that.
Of course you can cut back on my budget by eating at cheaper establishments ( I certainly don't go 5 star ) and buying from supermarkets and convenience stores of which there are an abundance.

well i worked out the prices for my accomodation, and it works aout at about £200 excluding my stay at disney. i will be mainly staying at youth hostels and possibly a mates house one weekend.

so do you think rounghly £800 will be enough to live on?

I spent a month in Tokyo on $600USD (60,000Y)for transportation and food. I only ate twice a day, no snacks, only drank water. I only traveled within Tokyo, and only to one prefecture each day.

The downside was having to eat prepackaged food and no snacks, and having to budget everything.

So...yes, you can definately make do with your budget, but you need to look into what level of comfort you want during those 17 days.

well if im honest, im not really looking to be dining at the finest japanese restaurants or living the life of luxury.

basically im going to be a student with the money i save now until september when i start my degree and what i have left after my loan in march.

i dont eat much anyway and only drink water too. if anything i will probably stick to local japanese food as iv heard it cheaper, and i will take night coaches etc to reach my next place.

i just want to see as much of japan as i can on my buget