I'm wondering why you feel you need clothing made specifically for hiking. Any pair of synthetic fabric pants will do. If you don't already own a pair of slacks in synthetic fabric, you should be able to purchase inexpensive nylon track pants at any discount sporting goods store or big box store (WallyWorld, Kmart, Target, etc.). Look in the athletic departments of the big box stores rather than the outdoor section. That's what I have usually worn for backpacking. I did buy a pair of convertible (zip-off legs) pants once, but found them highly uncomfortable thanks to the zippers on the legs. They are still sitting in my closet unused.

If you feel that you absolutely must spend the $$$ for the expensive stuff, a google search should tell you the difference between EU and US sizing. The manufacturer website should disclose the measurements that go with each size. I personally have found it impossible to buy clothing without trying it on, since the sizes vary so much from model to model.

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