Hello and thank you for allowing me to assist you.
In many cases you work out the gain or loss when you dispose of land in the same way as for other assets. Your gain will be calculated as the difference in your cost and the sale. This would mean that £840,000 would be your gain. You will be allowed your allowance for the gain £11,000.That will drop the taxable portion down to £829,000.
If you've spent extra money to buy, sell or improve your property, you can deduct certain costs.
Costs you can deduct include fees or commission for professional advice or services, for example, Capital Gains Tax valuations, solicitors' and estate agent or advertising fee.
Business Asset Roll-Over Relief would be provided if you sell or dispose of business assets (for example farmland that you farm) and reinvest the amount you received in certain other business assetsbut as you did not farm this yourself you cannot.
For 2013-14 Capital Gains Tax is charged at 18% or 28% for higher rate tax payers. (the tax rate you use depends on the total amount of your taxable income, so you need to work this out first )but it is safe to look to 28% with that amount of gain. £232,120