One of my colleagues has in her e-mail signature "Please think of the environment before printing this. 1 ton of paper = 17 trees". That's all fine and good. But how many sheets of paper do you get from a tree ? Indeed is there a standard for the size of a tree ? Since we're dealing with approximations I'm going to treat tons and tonnes as equal. 80 gsm paper is easy for the arithmetic. 1 SQ metre (A0 size) weighs 80 grams, so A1 size = 40g, A2 = 20g, A3=10g and A4 size is 5g. 200 sheets weigh 1Kg and 1 tonne, is 200,000 sheets. If 17 trees is 1 tonne, 1 tree is 0.06 tones, or 12,000 sheets. So 12 sheets = 1 millitree. WikiPedia says 24 sheets make a quire, which is a nice round 2 millitrees.

I wonder if can get this into any of those lists of conversions

You have to wonder how many of these units an army uses in a year ðŸ™‚

Hayden, do you know what percentage of a tree becomes paper. Does it 1 ton of paper need 1.001 tons of raw tree or 100 tons ?

I certainly don't know (I just took the sig at face value). If you don't either I'll have to do the research.

This is wrong. If 17 tree's = 1ton of paper then each tree is only 60Kg or 120Lbs (rough calc). Which results in (for pine) a tree that is only 4 Cubic Feet in size.