Most commercial airplanes fly at cruising altitudes between about 30,000 and 42,000 feet (approximately 9,100 to 12,800 meters) above sea level. This altitude range is chosen because the air is thinner, which reduces drag and allows planes to fly faster and more fuel-efficiently. Additionally, flying at these heights helps avoid weather disturbances, turbulence, and bird strikes, while also minimizing air traffic congestion

. Different types of aircraft have varying maximum service ceilings, which is the highest altitude they can safely maintain. For example, common commercial jets like the Airbus A320 cruise around 33,000 to 37,000 feet with a service ceiling near 39,000 feet, while larger aircraft such as the Boeing 747 can reach service ceilings up to 45,000 feet. Some private jets and military aircraft can fly even higher, with ceilings above 50,000 feet, but commercial flights generally do not exceed about 42,000 feet due to engine performance and cabin pressurization limits

. In summary:

• Typical commercial flight altitude: 30,000 to 42,000 feet
• Reasons for high altitude: fuel efficiency, less turbulence, avoiding weather and birds, and less crowded airspace
• Service ceilings vary by aircraft type but usually max out around 42,000 to 45,000 feet for commercial jets
• Some military and business jets can fly higher, up to about 50,000 feet or more