For every square inch, there is 14.7 pounds of air standing on top of you at sea level, or 14.7 psi. That 1 inch square column at sea level goes all the way to the edge of space, and actually gets wider as it goes up, so that's what you're measuring the weight of. But as the land goes up in elevation, that column is shorter and hence, it weighs less and you have less atmospheric pressure (about one pound less for every 2340 feet of elevation.) Variations in weather can also change the pressure slightly, but we'll ignore those.

Now if you want the entire atmosphere, you'll need the surface area of the entire globe (196,935,000 sq miles) converted into square inches (that will be a very large number...). And if you are going to be completely accurate, you would have to subtract off the atmospheric difference for any land areas with elevation above sea level. That would be quite a task to do and would require a very extensive land elevation data base.

But let's take a stab. There's 4,014,489,600 square inches per square mile which makes the earth about 7.9E+17 square inches, and we multiply that times something between the 14.7 psi at sea level and about 5 psi at Mount Everest, and we'll guess there's about 12 psi as a "possible average" number since most of the earth is water at sea level... And some of the rest has some elevation...

So 7.9E17 square inches * 12 psi = 9.5e+18 pounds of air. That's 4,700,000,000,000,000 tons.

Another blurtit answer claims 5,000,000,000,000,000 (five quadrillion) tons. So we're pretty close. q113455.html

That's heavy!

Now if you want the entire atmosphere, you'll need the surface area of the entire globe (196,935,000 sq miles) converted into square inches (that will be a very large number...). And if you are going to be completely accurate, you would have to subtract off the atmospheric difference for any land areas with elevation above sea level. That would be quite a task to do and would require a very extensive land elevation data base.

But let's take a stab. There's 4,014,489,600 square inches per square mile which makes the earth about 7.9E+17 square inches, and we multiply that times something between the 14.7 psi at sea level and about 5 psi at Mount Everest, and we'll guess there's about 12 psi as a "possible average" number since most of the earth is water at sea level... And some of the rest has some elevation...

So 7.9E17 square inches * 12 psi = 9.5e+18 pounds of air. That's 4,700,000,000,000,000 tons.

Another blurtit answer claims 5,000,000,000,000,000 (five quadrillion) tons. So we're pretty close. q113455.html

That's heavy!