GOV.UK Stamp Duty Calculator
There are many online calculators out there to help work out the Stamp Duty you may have to pay, however we always suggest going directly to the source!
Please see below a link to the Government Stamp Duty Calculator which will give an exact figure and breakdown of any Stamp Duty due. This will always be updated in line with any changes made to the Stamp Duty rules, as it is run by GOV.UK and so can be relied on to be accurate.