Ohmforge GPS Trip Stats (GPX → speed and distance)

What it is for

You recorded a ride, run or walk and want the numbers: distance, moving time, average and top speed, climb. Every fitness app counts a little differently. This tool reads a standard GPX track and works it out openly, with settings you can see and change.

It handles tracks from bike computers, sports watches, phone apps and the speedometer in Ohmforge's Pocket instruments. A trip logged there and downloaded as GPX gives the same numbers here. Distances are measured along the WGS84 ellipsoid, and speeds come from positions and times, never from a device's own speed field.

It needs a time on every track point. A route drawn on a map without times gives no speeds, and the tool tells you so.

Worked example

The second example is a phone recording of a walk: about 5 minutes out, a 10-minute coffee break (the recording paused, so the file has two track segments) and 7 minutes back. The phone recorded a point every 3 seconds with a few metres of scatter. With the stop speed at 1.5 km/h, a 15-second speed window and no jitter filter:

• Distance 1.33 km, moving time 11:57, total time 22:00.
• Moving average 6.7 km/h, maximum 9.0 km/h.

That is too fast for a walk. The scatter makes the track zig-zag, and every zig adds distance. Set the jitter filter to 8 m and run it again:

• Distance 1.05 km, moving time 11:54.
• Moving average 5.3 km/h, maximum 7.3 km/h, climb 7 m.
• A note says 141 points closer than 8 m to the previous one were left out.

The real path was about 0.98 km at 5 km/h, so the filtered result is much closer. The pause between the segments counts as stopped time and adds no distance.

How to read the result

• Distance follows the ground along the ellipsoid; climbing does not add to it.
• Moving time adds up the speed windows faster than the stop speed. Total time runs from the first to the last point, including pauses.
• Moving average is distance ÷ moving time, the number most cyclists quote. Average over total time includes every stop.
• Maximum speed is the fastest window of at least the chosen length. Longer windows ignore single GPS jumps.
• Climb counts only rises larger than the elevation noise threshold, because GPS heights scatter by several metres.
• Kilometre splits show time and speed for each full kilometre; the last split is the rest.

Tips and common mistakes

• For walking with a phone, try a jitter filter of 5–10 m. For cycling and driving, scatter matters less; leave it at 0.
• A maximum speed that looks absurd usually comes from one bad fix. Lengthen the speed window to 10 or 15 seconds.
• Set the stop speed to suit the activity: 1–2 km/h for walking, 3–5 km/h for cycling.
• Pausing and resuming a recording creates a new segment. That is good: the pause is not drawn as a straight line.
• Barometric heights from a watch are much steadier than GPS heights. Lower the elevation threshold for them.
• Never read a phone speedometer while you drive or ride. Look at the numbers afterwards.

FAQ

Why does my app show a different distance?

Apps smooth, snap to roads or drop points in different ways. This tool shows the raw geodesic distance with an optional, visible jitter filter, so you can see where the difference comes from.

Does the tool use the speed stored in my GPX file?

No. Speeds come from positions and times only, so files from all devices are treated alike.

Can I analyse a route without times?

You get an error, because every point needs a time stamp. Routes from planners have none; use RavingDesk's GPS converter for their distance.

Is my track uploaded anywhere?

The tool processes the file in memory to answer the request and does not keep it. In Ohmforge's speedometer, the trip stays in your browser until you download it.