How do you set your altimeter to read correct pressure altitude?

Setting the altimeter correctly is crucial for accurate altitude readings in flight. When flying below 18,000 feet, the altimeter should be set to the local barometric pressure, which is typically provided by air traffic control or available at the airport. This adjustment allows for accurate altitude readings relative to sea level and takes into account local weather variations.

Above 18,000 feet, standard pressure altitude is used, which is set to 29.92 inches of mercury (Hg). This helps maintain consistency in altitude reporting and air traffic control procedures as aircraft encounter various weather systems and pressure changes.

This two-part adjustment ensures precise altitude readings and proper separation between aircraft in the busy airspace above 18,000 feet, where standardization becomes essential for safety.