How much CGT will we be liable for??

Hi all...
Bought in Sept 1998 for 110,000 pounds (150000euro)

Principal residence from 1998 to July2004: 6 years
Rented July 2004-Feb 2008: 3 and a half years

Want to sell for 600,000 (House and site with FPP)
so willbe liablefor CGT on all of site I presume and how much of house value?? I reckon site price is about 200K and house 400K.

Any idea how much we willl lose to Tax Monster??

Thanks in advance as this will decide if we continue to rent out of sell the lot

Billions of threads about this. See this one for instance