Guides
Every guide pairs with a calculator on this site and explains what the formula does, what it ignores, and how to use the result.
The Basics
Dress & Sleep
- How to Read EN/ISO Sleeping Bag Temperature Ratings What the comfort, lower-limit and extreme numbers mean, how the thermal manikin test works, and where real life differs.
- Sleeping Warm at Night: A System Checklist Beyond the bag: pad R-value, damp insulation, dinner calories, the Hat Question and the small habits that decide cold nights.
Eat & Drink
- How Much Water to Carry Hiking Sweat rate basics, heat and humidity adjustments, and why one liter per two hours is only a starting point.
- Planning Backpacking Food: Calories per Day and Food Weight From daily calorie burn to kilograms in the pack: energy density, resupply math and realistic day-one menus.
Pack & Carry
Know the Conditions
- Altitude Sickness: Prevention Basics and Red Flags AMS, HAPE and HACE at a glance, the 500-meter rule, and the symptoms that mean descend now. Not medical advice.
- Cooking at Altitude: Boiling Point, Fuel and Time Why water boils cooler up high, how much longer rice and pasta take, and what it means for stove fuel planning.
Climbing
- The Fall Factor Explained What the ratio of fall distance to rope length really measures, why factor 2 is special, and what impact-force estimates leave out.
- Anchor Angles and Force on Each Piece Why a 120-degree angle doubles nothing and a 170-degree angle multiplies the load almost sixfold, with the vector math shown.
Guides and tools work together
Every guide is paired with the calculators it explains: the EN/ISO ratings guide behind the sleeping bag temperature calculator, the anchor angles guide behind the anchor force calculator, and so on. If you came here for a quick number, the tool matrix on the home page is the faster route.