# Hiking calculator

## Build the path by clicking on the map to get range and time estimates

Metric unit system
Imperial unit system

$V = V_0 * K_{slope} * K_{elevation} * K_{backpack}$

Where $V_0$ is a maximum safe and stable speed. Hiker achieves it descending -2.86° slope. Default $V_0 = 6 {km \over h}$ translates into 5 $km \over h$ on a flat terrain.

$K_{slope} = e^{-3.5 \left|{h \over l} + 0.05\right|}$ is defined by Tobler's hiking function. $h$ is elevation gain/loss and $l$ is a distance.

$K_{elevation} = e^{-9.80665 * 0.0289644 * (h - h_{acc}) \over {8.3144598 * 288.15}} = e^{-0.00011855(h - h_{acc})}$ and derived from the Barometric formula for atmosphere density. The idea here is that speed is decreased with atmosphere density decreasing, $h$ is elevation and $h_{acc}$ the elevation you are acclimatized for.

$K_{backpack} = (1 - {m_b \over 100})$ coefficient determines how backpack mass slows you down. $m_b$ is backpack mass to body mass ratio, percents.

Disclaimer: The calculator is intended for ballpark estimates. If you're not hiking in a ballpark use your discretion.