About

Driving across international borders or importing a vehicle often presents a critical challenge: speedometers reading in the wrong unit. Misinterpreting 100 km/h as 100 mph is a dangerous and illegal error. In the UK and USA, miles per hour is the standard, while most of the world uses kilometers per hour.

This tool acts as a digital dashboard converter. It provides quick, reliable translations of speed limits and vehicle specifications. It is designed with high contrast for quick readability and includes presets for common speed limits found on global highways.

Formulas

The conversion factor is derived from the definition of a mile, which is approximately 1.609344 kilometers. To obtain miles per hour, divide the kilometer value by this constant.

S_mph = S_km/h1.609344

Reference Data

km/h	mph	Speed Limit Zone
30	18.6	Residential / School Zone
50	31.1	Urban General Limit
80	49.7	Regional Road
90	55.9	Single Carriageway (EU)
100	62.1	National Speed Limit (General)
110	68.4	Expressway
120	74.6	Motorway (Standard)
130	80.8	Motorway (France/High-Speed)
160	100	High performance benchmark

Frequently Asked Questions

1 mph equals exactly 1.609344 km/h. This tool uses the full precision constant for calculation, though dashboards typically round to the nearest whole number.

Not exactly. 100 km/h is approximately 62.1 mph. Assuming it is 60 mph can lead to unintentional speeding if you are trying to match a 60 mph limit.

Yes. Sim racers often need to convert setups or telemetry data between Metric and Imperial units to match real-world car manuals.

Yes. It supports decimal inputs, useful for average speed camera calculations where fractions of a unit matter.