Trail Math: The National Park Service Uses This Simple Equation to Rate Their Trails
Whether traveling across the country to Yosemite National Park or finding a hike closer to home, the sense of adventure is part of the experience. However, how do you know if a hike is hard?
Videos by Outdoors
Before heading out on a trail, it’s always good to research to know what you’re getting yourself into. A hike could contain everything from high elevation to steep terrain and water crossings. Fortunately, most national, state and even local parks rate their trails, but is there a difference between a challenging hike in Florida vs. one in the Rocky Mountains?
The National Park Service uses a simple math equation to rate their trails. Here’s how their algorithm works.
First, they take the elevation gain and multiply it by two. Then, you’ll multiply that number by the miles you’ll hike. Finally, the square root of that last number is the numerical rating.
This equation may sound complicated, but the NPS uses this example to help you better understand. Imagine a 10-mile-long trail with a total of 2,200 feet of elevation gain. Here’s the math:
2,200 x 2 = 4,400
4,400 x 10 = 44,000
Square root of 44,000 = 209.8
The final product of 209.8 is then used to determine the difficulty level based on these categories:
Easiest – This has a rating of less than 50 and are trails that are generally suitable for anyone.
Moderate – Moderate gets all the trails rated between 50 to 100. These are great hikes for anyone who likes a slight challenge.
Moderately Strenuous – Rated between 100 to 150. Moderately strenuous hikes could be challenging for someone not used to exercise or hiking.
Strenuous – The algorithm for these trails hit between 150 and 200. Hikers should be prepared for longer and steeper hikes.
Very Strenuous – This rating is for anything over 200 and is generally only for experienced hikers. These trails are steep and could include rock scrambles and more.
So, let’s go back to the 10-mile hike with 2,200 feet of elevation and the rating of 209.8. The NPS would consider this trail as very strenuous. Meaning this is probably not something everyone should attempt.
What level of hikes do you look to do?
