About

OutdoorChar turns published outdoor-planning formulas into fast, honest calculators. No accounts, no uploads, no dark patterns - just the math, its assumptions and its sources.

How the numbers are sourced

Every calculator is built on a citable model: the Pandolf load-carriage equation for hiking energy, EN 13537 / ISO 23537 temperature-rating logic for sleep systems, the NWS wind chill index, the standard barometric formula and Clausius-Clapeyron relation for altitude calculations, Wilderness Medical Society consensus for ascent planning, and plain vector statics for climbing anchors. Each tool page states its formula and - just as important - what the formula ignores.

Our editorial position

Calculators are planning aids, not oracles. Where the outdoor world runs on contradicting rules of thumb, we show the model behind ours and let the assumptions be judged. Where a result touches safety - warmth margins, altitude, climbing forces - the page says so plainly and links the limits of the model. The FAQ and the guides carry the longer reasoning.

Privacy by architecture

The calculators run entirely in your browser. Inputs live in localStorage under oc.* keys and are never transmitted. See the privacy page for the full picture.

Contact

Corrections, formula disputes and feature ideas are all welcome at hello@outdoorchar.com. If you think a number is wrong, showing your working gets the fastest response.