Elevation Gain Calculator
Paste a list of elevations and get total ascent, total descent, net change and the biggest single climb — with a noise threshold, because raw GPS altitude invents climbing that never happened.
Nothing you type here is uploaded, stored or sent anywhere. It all runs in your browser.
Why two watches disagree about the same walk
Because they are adding up different noise. A GPS fix is good to a few metres horizontally and considerably worse vertically — the satellite geometry that makes horizontal position accurate makes altitude the weakest axis. A barometric altimeter is steadier, but it drifts with the weather: a front moving through during your walk shifts the reading by tens of metres over a few hours.
Now add up every rise. A track recorded every second on a flat valley path produces thousands of samples, each one a metre or two above or below the last, purely from measurement error. Sum all the positive differences and you have conjured a few hundred metres of climbing out of a level walk. That is the entire mechanism behind "my watch said 1,400 m and the guidebook says 900 m". Neither device is broken. One of them is filtering and the other is not, or they are filtering with different thresholds.
What the threshold does
The filter on this page is the standard one: hold a reference elevation, and only register a climb or a drop once the current point differs from that reference by more than the threshold — then move the reference. Small wander never accumulates; real climbing does, because it keeps going in one direction.
A threshold of 3 to 5 metres suits a barometric track. Raw GPS altitude often wants 8 to 10. Going higher starts eating real terrain: on a rolling ridge with 15-metre bumps, a 20-metre threshold flattens the ridge and under-reports the day. There is no universally correct value, which is precisely why devices disagree — and why a total quoted without a threshold is not really a measurement.
Reading the numbers
- Total ascent is what matters for timing. Not the summit height minus the trailhead height. A route that drops into two valleys on the way can have twice the climbing of a route that goes straight up to the same peak, and it will take correspondingly longer. Naismith and everything built on it use cumulative ascent.
- Ascent and descent should nearly match on a loop. If they differ by more than a few per cent on a route that returns to its start, your data has a problem — usually a dropped fix or a spike where the device reacquired satellites.
- The biggest single climb is the one that hurts. 900 m spread over a day is a walk. 900 m in one unbroken push is a different kind of day, and the number people should look at before choosing a route.
- Sample spacing changes everything. The same route, recorded once a second and once every 200 metres, gives very different raw totals. Denser data means more noise to accumulate, not more accuracy.
Getting elevations out of a GPX file
A GPX track is XML; every trackpoint carries an <ele> tag. Any text editor with search-and-replace, or a spreadsheet, will get you a column of numbers to paste here. If your mapping site exports a profile as CSV, the distance column can come along — paste both and this page will also give you the average gradient. Nothing you paste leaves your browser either way.
Questions people ask
Why is my elevation gain different on Strava, Garmin and Komoot?
They smooth differently. Some use the device barometer, some replace the recorded altitude with a digital elevation model of the terrain, and each applies its own threshold before counting a rise as a climb. None of them is lying; they are answering slightly different questions. Compare the same activity on the same platform over time, and do not compare totals across platforms.
What noise threshold should I use?
Three to five metres for a barometric track, eight to ten for raw GPS altitude. Set it to zero on this page first and look at the difference — the gap between the raw and filtered totals tells you how noisy your particular data is, which is more useful than any recommended value.
Is total ascent the same as the height of the mountain?
Only on a route that climbs without ever dropping. Total ascent adds up every upward metre you walk, including the ones you have to reclimb after a descent. It is always at least as large as summit height minus start height, and on a ridge traverse it can be far larger.
Can I paste a distance column as well?
Yes. Two numbers on a line are read as distance then elevation, and the page then also reports total distance and average gradient. Kilometres go with metres and miles go with feet, matching the unit you pick.
Does this upload my track?
No. The parsing and the arithmetic happen in your browser. There is no backend on this page and nothing you paste is stored or sent anywhere.
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