About Trailhead Lab

Who builds this

Trailhead Lab is maintained by a small group of long-distance hikers, trip leaders, and one retired NOLS instructor. None of us are meteorologists, physicians, or SAR coordinators. We are weekend trip planners who kept needing the same niche math and decided to publish it. Each tool lists the standards we relied on (NWS, NOAA, EN/ISO 23537, Tobler 1993, NPS Bear-Country guidance, etc.).

If you find a tool that disagrees with a field-tested source — for example, our pace model is too fast on talus, or our campsite score is too generous near avalanche runouts — please tell us. We document changes openly on each tool page.

What these tools are good for

• Pre-trip planning: comparing two routes, packing the right amount of fuel, deciding if a water filter is fast enough.
• At-the-trailhead decisions: whether to launch on a high route given the cloud ceiling, whether to cross a creek that's running higher than forecast.
• Teaching: instructors who want a single page that produces a numeric answer plus a short paragraph explaining the reasoning.
• Backcountry audits: after a trip, you can re-run your plan with actuals to see where estimates diverged from reality.

What these tools explicitly are NOT

• Do not use the Wet Bulb tool to decide whether a 50 km ultramarathon is safe in a heat dome — use race medical guidance.
• Do not use the Lightning Distance timer in place of stopping the activity when you see a strike, regardless of countdown.
• Do not use the River Crossing score to send a novice group across an unfordable stream — use a guide.
• Do not use the Golden Hour tool to plan solar-eclipse or astronomy safety — that's outside our scope.

Editorial principles

1. No filler content. If a calculator doesn't earn its page, we delete it. We currently maintain 35; the next will be one we actually need ourselves.
2. Show the math. Every tool references a public standard or a derived formula you can audit. We do not black-box results.
3. Limitations are not a footnote. Each page has a clearly headed "Limitations" section before the FAQ. We want you to know where the math stops being honest.
4. No dark patterns. No auto-play, no popups, no fake "download" buttons, no pre-roll interstitials. If we ever add affiliate links, they will be in plain text with a disclosure.

Methodology notes

Most tools use a simplified model because the alternative — a full physiologically-based heat stress model, a true ray-traced solar position, a hydrologic river model — requires inputs we cannot reasonably ask a backpacker to collect at 5 a.m. on a ridge. We bias toward conservative rather than optimistic outputs. Where the field has a known standard (EN/ISO 23537, NWS Wind Chill, NOAA Heat Index), we use the standard; where it doesn't, we say so on the page.