Scoutmaster links to an excellent online tool to calculate how long it should take to finish your hike. The gadget at builds on the Naismith Rule, which is that the average pace is three miiles per hour, adding an extra half-hour for each thousand feet of ascent.

The wotzwot calculator adds variables based on fitness level, weight carried, steepness of terrain, basic walking pace, break time and a few more. Seems like it works: By adjusting only the fitness level I got to within a few minutes of my time on a recent 12-mile hike with 4200 feet of elevation gain. (Go here to convert feet to meters). The weight carried variable is the only weakness: it has two choices, light day pack and medium to heavy pack, but there’s a world of difference, timewise, between carrying 25 and 45 pounds. Maybe they left that out so they’d have something to put in the upgrade.