Train Speed Meter
A precise digital speed meter for your train journey. GPS-powered, real-time readings displayed directly in your browser — no installation needed.
Quick Answer
The speed meter reads your device's GPS receiver to calculate ground speed using satellite signals. It updates once per second and displays the result as a clean digital readout — no cables, sensors, or train hardware required.
- Reads GPS position and Doppler data from your smartphone
- Calculates instantaneous ground speed in real time
- Displays speed in km/h, mph, m/s, or knots
- Updates every second (1 Hz refresh rate)
Precision
GPS Doppler accuracy
Refresh Rate
Updates every second
Units Supported
km/h, mph, m/s, knots
Works Offline
After initial page load
How the Speed Meter Reads Your Velocity
Your smartphone receives signals from a constellation of GPS, GLONASS, and Galileo satellites orbiting at approximately 20,200 km altitude. The speed meter leverages two complementary methods to determine your velocity with high precision.
Doppler Shift Measurement
As your train moves, the frequency of satellite signals shifts slightly — a phenomenon called the Doppler effect. The GPS chipset in your phone measures this shift across multiple satellites simultaneously and calculates your speed directly from the frequency change, providing readings accurate to ±2 km/h.
Position Delta Calculation
The meter also tracks successive GPS position fixes. By measuring the distance between two positions and dividing by the time elapsed, it produces a second independent speed estimate. The GPS chipset fuses both methods — Doppler and position delta — into a single reliable velocity output.
Speed Meter vs Traditional Gauges
Traditional analog speedometers on trains measure wheel rotation using tachometer generators or pulse sensors on the axle. Our digital speed meter takes a fundamentally different approach — reading speed from satellite signals rather than mechanical components.
Analog Gauges
Conventional train gauges rely on axle-mounted sensors that count wheel revolutions per second. While reliable, they suffer from wheel-slip errors during acceleration, wheel-wear drift over time, and are only visible to the driver in the locomotive cab.
Digital GPS Speed Meter
The GPS speed meter is independent of train hardware — it works from any passenger seat. It is immune to wheel slip, requires no calibration, and provides additional data like heading, distance travelled, and maximum speed reached during your journey.
No Installation Required
Unlike onboard systems that require wiring and sensor mounting, the GPS speed meter runs entirely in your browser. Open the page, grant location permission, and you have an instant speed readout — nothing to install, nothing to configure.
Instant Startup
Traditional gauges need the train's power system to be active. The GPS speed meter is ready the moment your phone acquires satellite lock — typically within 2–5 seconds in open areas, even before the train starts moving.
Speed Meter FAQ
Open the Speed Meter
Start measuring your train speed in real time. Free, instant, and accurate to ±2 km/h — open the speed meter now.
Works on iPhone, Android & any modern browser · Always free