The elevation of an object is it's height above sea level. Sometimes elevation and altitude are using interchangeable, however, altitude is the vertical distance between an object and the earth's surface.

How do I find out my height above sea level?

An altimeter is a device that measures altitude—a location's distance above sea level. Most altimeters are barometric, meaning they measure altitude by calculating the location's air pressure.

How do I find height above sea level on Google Maps?

Check the altitude of a place

Search for a place, or adjust Google Earth until you get to the view you want. At the bottom right find the real-world altitude and the altitude of the camera. If you move the mouse to hover over different locations, the altitude updates.