Elevation Grade Calculator

Grade tells you how steep a climb is. It does not tell you how hard a hike is, and most grade calculators blur the two. The version of this one that ran until September 2026 did exactly that: it turned grade alone into a difficulty label. The calculator above keeps them apart. It gives you the steepness of the climb and, when you enter a whole route, a separate difficulty rating that also counts how far you walk.

How to Calculate Elevation Grade

Grade is rise over run: the elevation you gain, divided by the horizontal distance you cover to gain it, times 100.

Grade (%) = elevation gain ÷ horizontal distance × 100. Both numbers have to be in the same unit, so convert first: one mile is 5,280 feet, one kilometer is 1,000 meters.

A trail that climbs 1,500 feet457 m in 3 miles4.8 km: 1,500 ÷ (3 × 5,280) × 100 = 9.5%. That is the calculator’s default example, and it lands in the moderate band.

Grade, Degrees and 1 in X: Three Ways to Write One Slope

A 100% grade is not a vertical wall. It is 45 degrees, the slope where you rise as much as you move forward. To turn a grade into an angle, take the arctangent: angle = arctan(grade ÷ 100).

That is why grades sound steeper than their angles. A 10% grade is only 5.7 degrees, and a 20% grade, steeper than the target range of almost every built hiking trail, is 11.3 degrees. The slope drawing in the calculator is to true scale for the same reason: it shows you how little tilt a hard climb really has.

Road signs in the UK write the same slope as a ratio: 1 in 10 means one unit up for every ten along, which is a 10% grade. American trail guides often give feet per mile instead, which is the grade times 52.8, and metric guides give meters per kilometer, the grade times 10. The calculator shows all of them, and the chart below converts the common ones.

The Round-Trip Mistake

Guidebooks and apps give the elevation gain for the whole route, and the distance for the whole route too. Divide one by the other and an out-and-back comes out half as steep as it is, because you only climb on the way up. Shenandoah National Park’s own example hike, 10 miles16.1 km with 2,200 feet671 m of gain, averages 4.2% if you divide the gain by the full distance. The climb itself, over the first 5 miles8 km, averages 8.3%. Pick The whole hike, there and back in the calculator and it halves the distance for you.

A loop is a guess either way, since its climbing can sit anywhere along the route. Treating it as half up and half down is the neutral assumption.

Working Backwards: Elevation Gain From Grade

Flip the formula and you get the gain: elevation gain = grade ÷ 100 × distance. A 2-mile3.2 km climb at 8% gains 0.08 × 2 × 5,280 = 845 feet257 m.

Grade Conversion Chart

Every row below is computed, not copied from another chart. The last column shows where you actually meet that slope, taken from US Forest Service trail design standards and the federal accessibility rules for trails.

What Is a Steep Grade for Hiking?

There is no official cutoff, but there is a good yardstick: the grades trail builders design to. The US Forest Service gives every class of hiking trail a target grade, the range most of the trail should sit in, and a short-pitch maximum, the steepest it may get for brief sections.

So a sustained 8% is what a developed trail is built for, and a sustained 20% is steeper than the target of every class except the most primitive. The steepness bands in the calculator follow the same lines: under 5% gentle, 5 to 10% moderate, 10 to 15% steep, 15 to 25% very steep, and 25% and up extreme.

How Many Feet per Mile Is Steep?

In climb-rate terms the same bands are: under 264 feet per mile50 m per km gentle, 264 to 528 feet per mile50 to 100 m per km moderate, 528 to 792 feet per mile100 to 150 m per km steep, 792 to 1,320 feet per mile150 to 250 m per km very steep, and anything over 1,320 feet per mile250 m per km extreme.

A round figure like 1,000 feet per mile189 m per km works out to 18.9%: very steep on this scale, and past the target grade of every developed trail class.

Hike Difficulty: Why Grade Alone Is Not Enough

Grade measures the slope, not the day. A 10-mile16.1 km walk that climbs 1,000 feet305 m over its whole length averages 1.9%, which any steepness scale calls gentle. It is still 10 miles16.1 km. The old version of this calculator rated that hike Easy, because it judged difficulty by grade alone.

Shenandoah National Park’s hiking difficulty rating fixes that by multiplying the two things that make a hike hard, how far you go and how much you climb, and then taking the square root:

Difficulty rating = √(elevation gain in feet × 2 × distance in miles)

That 10-mile16.1 km hike rates √(1,000 × 2 × 10) = 141.4: moderately strenuous. The park’s own example, 10 miles16.1 km with 2,200 feet671 m of gain, rates 209.8: very strenuous. The calculator runs this on any route of half a mile800 m or more and shows it under the grade.

The Shenandoah Difficulty Scale

The calculator’s moving time uses book time instead of the park’s planning pace, and lets you adjust it for your pace, the trail and your pack. Hiking time below explains the model.

Energy Miles

Paul Petzoldt, founder of the National Outdoor Leadership School, proposed counting every 1,000 feet305 m of climbing as two extra miles3.2 extra km on the flat. The total, energy miles, puts a short steep hike and a long flat one on the same footing: 6 miles9.7 km with 1,500 feet457 m of gain comes to 9.0 energy miles.

It is a rule of thumb, and it has been tested. Researchers at Western Carolina University measured the energy cost of walking a mile on the flat and of climbing 1,000 feet305 m, with and without a 44.5 lb20.2 kg pack. The climb came out at about 1.6 energy miles, not 2, and the figure differed between women and men (1.32 to 2.02). Using 1.6, the same hike is 8.4 energy miles instead of 9.0, so treat the calculator’s figure as slightly generous to the climbing.

The Metric Version

The formula is defined in feet and miles. In meters and kilometers it becomes rating = √(meters gained × kilometers × 4.08). A 6.2-mile10 km hike with 1,640 feet500 m of gain rates √(500 × 10 × 4.08) = 142.8, the same answer as the feet-and-miles version. Enter meters and kilometers in the calculator and it converts for you.

Where the Rating Falls Short

• Short, steep hikes rate too easy. The park says so itself: its Dark Hollow Falls trail computes to 36.3, in the Easiest range, and is rated Moderate because it is steep over a short distance. That is why the calculator puts steepness and difficulty side by side.
• It counts the climb, not the descent. Your knees and quads pay for the way down, and the formula does not see it.
• It knows nothing about the ground. Scree, roots, snow, heat, altitude and a heavy pack all make a hike harder at the same rating.
• The top band is open-ended. A 210 and a 400 both read very strenuous, though the second is a far bigger day.

Hiking Time Calculator: How Long Will the Hike Take?

Enter the whole route and the calculator also gives the moving time, split into the time for the distance and the time for the climb, with your pace in minutes per mile or kilometer and your average speed. Add the time you set off and it tells you when you should be back.

Moving time (minutes) = miles × 19.5 + feet gained ÷ 1,000 × 30, then × your pace, the trail surface and your pack.

That is book time: 19.5 minutes per mile12.1 minutes per km on the flat plus 30 minutes for every 1,000 feet305 m of climbing. It is a slightly quicker version of Naismith’s rule, the Scottish rule of thumb of one hour per 3 miles5 km plus one hour per 2,000 feet600 m of ascent, which comes to 20 minutes a mile. A 5-mile8 km hike with 2,000 feet610 m of gain takes 97.5 + 60 = 2 h 38 min of moving time. On a rough trail it becomes 3 h 9 min.

Pace, Trail Surface and Pack

How Long Does It Take to Hike 3, 5 or 10 Miles?

Moving time at a normal pace, with a regular pack on a smooth trail, from the same model as the calculator. Rough ground and breaks come on top.

Average Hiking Speed

On the flat, book time is a moving speed of about 3.1 mph5.0 km/h. Climbing pulls the average down fast: the 5-mile8 km example above averages 1.9 mph3.1 km/h. Shenandoah plans with 1.2 to 1.5 mph1.9 to 2.4 km/h on its trails, depending on the difficulty level in the table above. Use whichever matches how you walk, and add your breaks: the calculator only counts time on the move, so leave early enough to finish in daylight.

How to Use the Calculator

1. Enter the distance. For a single hill, road or ramp, use the length of the climb. For a hike, use the route distance from your guidebook or mapping app. The formula wants horizontal distance, but at trail grades the difference is small: at 12% the distance along the slope is only 0.7% longer.
2. Enter the total elevation gain. That is every climb added up, not the summit height minus the trailhead height. A route with three climbs counts all three.
3. Say what the distance covers. Just the climb is plain rise over run. The whole hike, there and back halves the distance for the grade and uses the full distance for the difficulty rating.
4. Read both results. Steepness tells you how the climb will feel. Difficulty tells you how the day will feel. The arithmetic under the results shows how each number was reached, and the copy button gives you a link that reopens the same result.
5. Set your pace, the trail surface and your pack under Hiking time, and the time you leave. The moving time, your pace and average speed, and the time you should be back update as you change them.

Sources

• National Park Service, How to Determine Hiking Difficulty, Shenandoah National Park. The difficulty formula, the five levels, the planning paces and the Dark Hollow Falls caveat.
• McNeff M, Phipps M. The Validity of Petzoldt’s Energy Mile Theory. Journal of Outdoor Recreation, Education, and Leadership. The measured 1.6 energy miles per 1,000 feet305 m of climbing.
• USDA Forest Service, Hiker/Pedestrian Design Parameters (Forest Service Handbook 2309.18), for target grades, short-pitch maximums, surfaces and obstacles by trail class, and the National Trail Classification System that defines those classes.
• U.S. Access Board, Guide to the ABA Accessibility Standards, Chapter 10: Outdoor Developed Areas, for the running-slope limits on accessible trails.
• American Trails, Building Sustainable Trails: Key Design Elements, for the ten percent average grade guideline.

Other calculators:

• What to Wear Hiking: Gear Planner
• Hiking Calorie Calculator
• Backpack Weight Calculator
• Trekking Pole Height Calculator
• Hydration Calculator
• Hiking terms glossary, for elevation gain, switchbacks and scrambling