[qume]

So from that page I did a rough calculation - the following is in billions of tons of the animals alive in 2006:

Chickens 34 Cattle 560 Sheep 70 Ducks 2 Pigs 75 Total 741 (animals)

Humans 420

Looks like there are nearly two measures of livestock weight for every one of humans.

[beloch]

~7.6 billion humans weigh 420 billion tons? That would mean the average human weighs 55 tons! Talk about an epidemic of extreme morbid obesity!

[qume]

Good spotting, for humans that's Million tons.

It's going to be quite some time until humans weigh 55 tons, but if you interpret the graph like people pitching to investors like to, we'll get there.