Is your PPI U-L?

posted Jul 17, 2013, 9:06 AM by Paul Wagner

What does Ultra-light backpacking mean?  Most people use a definition that sets a weight limit of 12 pounds on your pack, not including food and water.  To get to those levels, you have to pack pretty carefully, and you have to spend at least some money on a light but warm sleeping bag, tent/tarp, and pack. 


We’re close to that level.  M starts her trips at between 11 and 13 pounds, and P does the same—except we ALWAYs carry a bear canister with us.  And that adds two pounds to P’s pack.  So technically, he’s at 14 pounds.  But if we count the canister as part of the food and water (after all, if there were no food, there would be no bear canister) they he is right at the upper edge of Ultra-light as well.


P posing near the bridge. ©

But since P is a cyclist, he has another way of looking at weight.  It doesn’t matter how much you carry, it matters how much you weigh, pack included.  In cycling, a lightweight bike will only get you so far—then you have to start dropping the pounds off your body, not off your bike. 

So it might make more sense to measure how much total weight you have to carry on the trail and over that pass.  P weighs in at about 175, and if you add the 14 pounds of his pack and clothes, the total is 187.  Of course, we have to come up with some way of balancing this against the size of each person.  If you are 6’10”, you are going to carry more weight, and you can easily do that. 

And that leads us to our weight per inch of height ratio.  Divide your total weight on the scale by your height in inches, and you should get a number between 2.5 and 4.  

Since P is 5’10”, (seventy inches of height) and his pack is 187, he gets a PPI (pounds per inch) of 2.67 without food and water.  With food and water for an eight day trip, the PPI goes up to a nice round 3.0.  As long as you are packing light, and your weight is within the suggested guidelines for your height, you should be about the same. 

But if all those dollars you have spent on ultra-light gear are being off-set by a heavier than average body, then you know what you have to do:  buy even lighter equipment, obviously.

M’s PPI?  That’s classified.  Sorry.   But it is certainly less  than P’s.