by Guest » Fri Aug 26, 2005 6:04 pm
1) You can weigh it
2) If you know what it is a liter of, you can look up the density in a reference book and multiply by it.
Obviously, a liter of feathers and a liter of lead have different weights, so there is no universal conversion.
Why is this question asked nearly every day by people expecting a simple answer, when the idea is so contrary to every day life. An empty bucket (really full of air) weighs less than when you put anything in it, yet it is the same volume.