Vertical miles are not horizontal miles
The arithmetic is identical — divide feet by 5,280 — but the meaning is not. Walking 0.76 miles along a road takes about fifteen minutes. Climbing 0.76 miles vertically, which is 4,000 feet, takes most people two hours or more.
This is why hiking guides quote distance and elevation separately rather than combining them. The two numbers describe different costs, and the vertical one usually dominates.
| Gain | Vertical miles |
|---|---|
| 500 ft | 0.0947 mi |
| 1,000 ft | 0.1894 mi |
| 2,000 ft | 0.3788 mi |
| 3,000 ft | 0.5682 mi |
| 4,000 ft | 0.7576 mi |
| 5,280 ft | 1 mile exactly |
| 14,505 ft (Mt Whitney) | 2.747 mi above sea level |
| 29,032 ft (Everest) | 5.498 mi above sea level |
Naismith's rule, in feet
The standard planning heuristic, formulated by Scottish mountaineer William Naismith in 1892, allows one hour per three miles of horizontal distance plus an additional hour per 2,000 feet of ascent.
In practice most people find 30 minutes per 1,000 feet closer to reality once packs, terrain and rest stops are accounted for. Either way, the vertical component of a hike routinely accounts for more than half the day.
Worked example: a 10-mile route with 3,000 feet of gain is about 3 hours 20 minutes flat, plus 90 minutes for the climb, giving roughly 5 hours. The 0.57 vertical miles cost nearly as much as the 10 horizontal ones.
Going the other way, miles to feet does the reverse conversion. If you want a figure already worked out, conversion chart lists the common ones, and about & methodology documents every constant used here and where it comes from.
Naismith's rule: 1 hour per 3 miles, plus 1 hour per 2,000 ft of ascent. Adjust the vertical term upward if you are carrying weight.
Altitude, gain and elevation are three different numbers
Altitude is height above sea level — the summit figure. Elevation gain is the total climbing on a route, which on an undulating trail can far exceed the difference between start and summit. Net gain is simply the difference between the two endpoints.
A ridge traverse might have 200 feet of net gain and 4,000 feet of cumulative gain. Planning off the wrong one is how a day hike becomes an epic.
When a trail description gives a single elevation figure, check which it means. Cumulative gain is the one that predicts effort.
- Altitude: height above sea level.
- Net gain: summit minus trailhead.
- Cumulative gain: every uphill metre added together — the one that matters.
- 1,000 ft of gain = 0.19 vertical miles ≈ 30 extra minutes.
Why apps disagree about elevation
If three people walk the same trail with three different apps, three different numbers come back — sometimes 20 per cent apart. This is not random.
The barometric altimeter in better watches measures air pressure. It is accurate over short periods but is affected by weather: an approaching storm can add hundreds of feet of phantom climb across a full day.
GPS-derived elevation is noisier vertically than horizontally, sometimes by 30 to 50 feet at any instant. Accumulated over a long trail, that noise shows up as false gain.
Apps that use a digital elevation model — a terrain map rather than a sensor — are the most consistent, but they miss climbs shorter than the map's resolution. No method is perfect; what matters is using one method consistently when comparing two hikes.
Planning water and rest by climb
Elevation gain predicts fatigue better than distance does. An 8-mile hike with 500 feet of climb is easy; a 4-mile hike with 3,000 feet is hard.
A practical rule: count every 1,000 feet of climb as an extra 2 miles of flat walking. So 4 miles and 3,000 feet feels like a 10-mile walk in both time and effort.
Descent deserves the same respect. The same 3,000 feet — 0.568 miles — going down loads the knee with two to three times body weight on every step, which is why the return leg of a point-to-point hike is often harder than expected.
Grade: the number that actually matters
Grade is elevation gain divided by horizontal distance, expressed as a percentage. A climb of 1,000 feet over one mile (5,280 feet) is a grade of 18.9% — very steep.
For reference: roads rarely exceed 10%. A trail at 15% is hard work. A trail at 25% involves using your hands in places.
The calculation is simple provided the units match. If elevation is in feet and distance is in miles, convert the miles to feet first by multiplying by 5,280. Mixing the two is the single most common way to arrive at a grade that is off by a factor of 5,280.
Related conversions: ft/s to mph for speed, sq ft to sq miles for land area, and feet to mil for the unit people most often confuse with the mile.
Estimating time from climb
Naismith's rule is the classic estimate: one hour per 3 miles of horizontal distance, plus one hour per 2,000 feet of ascent.
So a 6-mile trail with 3,000 feet of gain is about two hours for the distance plus an hour and a half for the climb — roughly three and a half hours.
The rule is optimistic in heat, in mud, and with a heavy pack. Adding 20 to 30 per cent for conditions is more realistic than trusting the raw figure.
Key takeaways
- Elevation converts like any length: divide feet by 5,280.
- A vertical mile is 5,280 ft — Everest is 5.5 miles above sea level.
- Budget roughly 30 minutes per 1,000 ft of climb on top of flat pace.
- Cumulative gain, not net gain, is what predicts how hard a route will be.
Try it yourself
Ft to Miles Calculator
Convert feet to miles and back, live as you type.