See your real GPS speed in km/h, mph, m/s or knots, with distance covered, top speed, average speed and pace per kilometre.
The obvious way to compute GPS speed would be to take two positions and divide the distance by the elapsed time. Plenty of tools do exactly that, and it is why their readings jitter: each position carries several metres of error, so the difference between two of them carries both errors, and the result swings far more than the real speed does. Modern receivers do better. They measure the Doppler shift of the satellite signal carrier, that is, how much the received frequency is displaced by relative motion. That measurement is independent of the position solve and much more stable, and it is what appears in `coords.speed` when the device provides it. This tool uses that value whenever it exists and only falls back to dividing distance by time when the device leaves the field empty, which is stated on screen. Distance covered gets two safeguards that change the result considerably. Readings with accuracy worse than thirty-five metres are dropped from the total, because a very imprecise fix teleports the track and invents kilometres that never happened. And movement below half a metre per second is not added, since a stationary GPS wanders a few metres per minute on noise alone, which would turn a wait at a traffic light into phantom distance. The average is computed over moving time, not total time. Both are shown separately because they answer different questions: a runner wants the pace while actually running, and a traveller wants to know how long the whole trip took, stops included.
These references help contextualize formulas, standards, APIs and limitations used on this page. They do not replace professional validation when a result has legal, financial, medical or operational impact.
Usually yes, for a curious reason: car speedometers are deliberately optimistic. Regulations in many countries allow the instrument to read higher than the true speed but never lower, so manufacturers calibrate with margin. Dashboards commonly read 5 to 10 % high. GPS measures actual displacement and has no such bias, but it is also not the legally required instrument.
Tap to turn on GPS. Your location is used only to compute the result on this screen and is never sent to our servers.
If you are driving, do not look at your phone. Use the vehicle own speedometer, which is the legally required instrument, and save this tool for when you are a passenger, on foot, on a bike, or stopped.
Your position is used only on this screen to compute speed and distance. No coordinate and no track leaves your browser, and nothing is stored when the page closes.