Help understanding stamp duty

Stamp Duty is a tax that you have to pay if you buy a property worth £125,000 or more. The amount you pay depends on the purchase price. The calculation is based on a percentage of varying portions of the purchase price as below: First-time buyers are exempt from the duty of any purchase up to the value of £300,000 and liable to 5% of the portion above up to the value of £500,000

PROPERTY OR LEASE PREMIUM OR TRANSFER VALUE SDLT RATE
Up to £125,000 Zero
The next £125,000 (the portion from £125,001 to £250,000) 2%
The next £675,000 (the portion from £250,001 to £925,000) 5%
The next £575,000 (the portion from £925,001 to £1.5 million) 10%
The remaining amount (the portion above £1.5 million) 12%

Example

If you buy a property for £275,000, the SDLT you owe is calculated as follows: