How much paper can be made from a tree? Or, alternatively, how many trees are needed to make a given amount of paper?

There is no simple answer to these questions, and all calculations can be no better than “ballpark estimates.” Paper is made from a mix of types of trees. Some are hardwood, some are softwood. In addition, some are tall, some old, some wide, some young, some thin. Many of the “trees” used to make paper are just chips and sawdust. So how can one talk about a “typical tree?”

Conservatree has tracked down some ways to make ballpark estimates more reliable than in the past. Here’s some considerations to evaluate.

* Kinds of Paper—Paper made in a “groundwood” process (e.g. newsprint, telephone directories, base sheet for low-cost coated magazine and catalog papers) uses trees about twice as efficiently as paper made in the “kraft” or “freesheet” process (e.g. office and printing papers, letterhead, business cards, copy paper, base sheet for higher-quality coated magazine and catalog papers, advertising papers, offset papers).
* Coated or Uncoated?—The fiber in a coated paper (most often used for magazines and catalogs, with a clay coating that may be glossy or matte, or other finishes) may be only a little more than 50 percent of the entire sheet, because the clay coating makes up so much of the weight of the paper. As a ballpark estimate, you can use .64 as the fiber estimate for coated papers compared to the entire weight of the sheet. (Fiber estimate calculation by Alliance for Environmental Innovation.)

Claudia Thompson, in her book Recycled Papers: The Essential Guide (Cambridge, MA: MIT Press, 1992), reports on an estimate calculated by Tom Soder, then a graduate student in the Pulp and Paper Technology Program at the University of Maine. He calculated that, based on a mixture of softwoods and hardwoods 40 feet tall and six to eight inches in diameter, it would take a rough average of 24 trees to produce a ton of printing and writing paper, using the kraft chemical (freesheet) pulping process.

If it is assumed that the groundwood process is about twice as efficient in using trees, then we can estimate that it takes about 12 trees to make a ton of groundwood and newsprint. (The number will vary somewhat because there often is more fiber in newsprint than in office paper, and there are several different ways of making this type of paper.)

Some Calculations
* One ton of uncoated virgin (non-recycled) printing and office paper uses 24 trees.
* One ton of 100-percent virgin (non-recycled) newsprint uses 12 trees.
* A “pallet” of copier paper (20-lb. sheet weight, or 20#) contains 40 cartons and weighs 1 ton. Therefore, one carton (10 reams) of 100-percent virgin copier paper uses .6 trees; one tree makes 16.67 reams of copy paper or 8,333.3 sheets; one ream (500 sheets) uses six percent of a tree (and those add up quickly!); one ton of coated, higher-end virgin magazine paper (used for magazines like National Geographic and many others) uses a little more than 15 trees (15.36); and one ton of coated, lower-end virgin magazine paper (used for news magazines and most catalogs) uses nearly eight trees (7.68).

How do you calculate how many trees are saved by using recycled paper?

* Multiply the number of trees needed to make a ton of the kind of paper you’re talking about (groundwood or freesheet).
* Then multiply by the percent recycled content in the paper.

For example, one ton (40 cartons) of 30 percent post-consumer content copier paper saves 7.2 trees; one ton of 50 percent post-consumer content copier paper saves 12 trees.

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