Speed tools
Speed Converters, Odometer & HUD Tools
Trip odometer, heads-up display mode and speed unit converters.
100 km/h to mph100 km/h is 62.14 mph (100 ÷ 1.609344). See where 100 km/h is the speed limit, what 0–100 km/h means, and a 80–120 km/h to mph chart.Open tool 100 mph to km/h100 mph is 160.93 km/h (100 × 1.609344). It is above every US speed limit (max 85 mph). See US rail track-class speeds and an 80–120 mph chart.Open tool 120 km/h to mph120 km/h is 74.56 mph (120 ÷ 1.609344). Where 120 km/h is the limit (India's expressways, UK motorway equivalent), US comparison and a 100–140 chart.Open tool 20 mph to km/h20 mph is 32.19 km/h (20 × 1.609344). It is the default limit on Wales's restricted roads since 2023 and a fast bike pace. Chart 5–40 mph in km/h.Open tool 30 mph to km/h30 mph is 48.28 km/h (30 × 1.609344). The UK built-up limit, plus Highway Code stopping distances at 20–70 mph in metres and km/h, and a 10–50 mph chart.Open tool 60 mph to km/h60 mph is 96.56 km/h (60 × 1.609344). It is the UK national speed limit on single carriageways and the 0–60 benchmark. Chart 40–80 mph in km/h.Open tool 
Altitude: What Is My Elevation?What is my elevation? Free GPS altimeter: see your altitude in feet or meters, its vertical accuracy, and your lowest, highest and total climb.Open tool km to miles ConverterConvert km to miles instantly: divide by 1.609344. 5 km = 3.11 miles, 10 km = 6.21 miles, marathon = 26.22 miles. Free converter, race table and tricks.Open tool km/h to mph ConverterConvert km/h to mph instantly: divide by 1.609344. 100 km/h = 62.1 mph. Free converter, full 5–300 km/h table, mental-math tricks and road-sign guide.Open tool Knots to mph ConverterConvert knots to mph instantly: 1 knot = 1.15078 mph. Free knots to mph calculator, quick chart, formula, and US boating, aviation and hurricane examples.Open tool miles to km ConverterConvert miles to km instantly: multiply by 1.609344. 1 mile = 1.61 km, 10 miles = 16.09 km, 100 miles = 160.93 km. Free converter, chart and mental tricks.Open tool mph to km/h ConverterConvert mph to km/h instantly: multiply by 1.609344. 60 mph = 96.6 km/h, 65 mph = 104.6 km/h. Free converter, quick table and Canada driving guide.Open tool mph to Knots ConverterConvert mph to knots instantly: knots = mph × 0.868976. Free converter, quick chart from 1 to 500 mph, mental shortcut and US boating and aviation examples.Open tool mph to m/s ConverterConvert mph to m/s instantly: 1 mph = 0.44704 m/s exactly. Free calculator, full chart, mental shortcut, wind (Beaufort) and sprint examples.Open tool 
Online CompassFree compass online: open it on your phone to see your heading in degrees and a 16-point direction, with magnetic and true north. No app, no download.Open tool Speed ConverterFree speed converter for mph, km/h, knots, m/s, ft/s and Mach. Exact factors, a full conversion chart, unit history and worked US examples.Open tool 
Speed Distance Time CalculatorFree speed calculator: solve speed, distance or time from the other two, in mph, km/h, knots or m/s, plus true average speed for multi-leg trips.Open tool 
Speed of Sound (Mach to mph) ConverterThe speed of sound is 761 mph (1,225 km/h) at sea level and 660 mph above 36,000 ft. Free Mach to mph converter, altitude table and formula.Open tool 
Speedometer Calibration CalculatorCheck your speedometer calibration against GPS or a timed mile. Get the percent error, a correction factor and a corrected speed table in mph.Open tool 
Tire Size CalculatorFree tire size calculator: compare two tire sizes for diameter, sidewall, width and revs per mile, see plus sizes and your true speed at 60 mph.Open tool 
Trip OdometerFree online distance tracker: a GPS trip odometer that counts miles or km and moving time, copies the total for your mileage log and saves GPX. No app.Open tool FAQ
Frequently asked questions
What is a trip odometer?
A trip odometer measures the distance of one journey. The speedometer’s trip distance adds up GPS distance while you move and ignores jitter while you stand still.
What is HUD mode?
HUD mode mirrors the display so it reads correctly as a reflection on your windscreen at night.
How do I convert km/h to mph?
Multiply km/h by 0.621371. 100 km/h is 62.1 mph.
Looking for something else? Browse all 38 speed tools or start with the online speedometer.