This is a question I see thrown about quite alot, especially with people who are tinkering with the idea of giving up the 9 till 5.

Before I run into how I work out costs I must state one thing, being a freelancer IS hard work.... Theres no more 9 till 5 and you will find yourself working at weekends and evenings!  Also on the flip side to that, I can gaurantee all the work you have had coming in while you are stilldoing you're 9 till 5 job WILL just dry up - I don't know what it is, but it seems to happen to everyone.  You must spend some time actively looking for work in the early days, even if you have a few large projects on the go still look for more (Because when they finish you will find yourself with nothing to do, and nothing to do = no money!)

Anyway back on track ....  I find the best way to price for jobs, is to price by the day; Although obviously you need to work out you're daily rate first, which is actually quite simple.

1.) How much are you looking to make in your first year (Remember don't be greedy, but you need to pay the bills)

Lets say £30,000 for example purposes

2.) Obviously you don't want to work weekends (But you will), so the wage above needs to be divided by the amount of week days in a year - I use 260 which is more or less correct

260 Work days in a year

3.) Days off - Now you have to cater  for the unexpected, being ill, having to see the accountant (even doing some accounts yourself), going to the dentist, business lunch with client which ends up in a drinking session etc.. etc.. So if we allow for 2 weeks in the year, I think that should be ample to begin with.

260 - 14 =  246 Days

Excellent ... We can now work out our daily and even hourly rate (But don't forget your going to pay tax out of this!!)

Hmmm that damn tax thing!  Now we are getting somewhere...  So add 19% to your figures to allow for your tax & National Insurance

You're Daily Rate:  (£30,000 / 246 Days = £121.95  + 19%) = £145.12

You're Hourly Rate: (£121.95 / 8 = £15.25 + 19%) = £18.15

Working out how long it will take you to make each site is somthing only you will know, and will become alot easier in time...  Heres a very rough example of how I would work out a site using the above figures

Needs: Client wants a nice designed site that has full content management. 

Design (1 day): £145
Design Tweaks after client input (0.5 Days): £72.50

Website Template Build (1 day): £145
Setup / Integrate into Content Management System / build out / Talk Client through CMS (2 days): £290.00

Website Hosting (Yearly Charge): £99.00

Total Website Price: £751.50