This shows you how to calculate energy savings that the sewing club has generated this year.

We calculated that a 100 pound person could walk at least 308.6896 miles and use up the same amount of energy that it would take to make a single pair of jeans. We arrived at this number this way:

We assumed that a 100 pound person walking 3 mph burns about 3.1 Calories in a minute. This imformation came from :  <a href="http://brianmac.co.uk/energyexp.htm">http://brianmac.co.uk/energyexp.htm</a>.      Then, we multiplied this times 20 minutes to get the number of Calories burned in a mile of walking, which gave us 62 Calories per mile. There are about 239 Calories in a megajoule (a megajoule is 1 million joules. A Calorie is 1000 calories. The energy iin food is measured in Calories, not calories). So, there are about 239.2344498 Calories per megajoule.

We can now calculate the number of miles a 100 pound person walks using one megajoule of energy: 3.858620157 miles per megajoule.

The other piece of information we need to know is how many megajoules of energy it takes to make a pair of jeans. This varies for each manufacturer, but based on the Levi company's published figures in <a href="http://sustainable.bizjournals.com/green/Levi_cuts_pattern_for_a_greener_bottom_line.htr">http://sustainable.bizjournals.com/green/Levi_cuts_pattern_for_a_greener_bottom_line.htr</a> we estimated at least 80 megajoules of energy is used to make a pair of jeans. This is a very conservative estimate, since it is about 20% of Lev's stated estimate.

So, our final calculation tell us that the energy that it it takes to walk  308.6896 miles is about the same amount of energy that it takes to manufacture a pair of jeans.

If we assume that mending a pair of jeans kept a person from having to buy a new pair, and that keeps a factory from having to make that new pair, we can multiply the number of jeans we mended by 308.6896 miles to see how far a person could have walked using the amount of energy the Sewing Club saved.