Driving speed conversions

Australian speed limits are in kilometres per hour. The United States and the United Kingdom use miles per hour, so a speed quoted from an American car review or a British road guide needs converting before it means anything on an Australian road. One kilometre per hour is 0.621371 miles per hour, and one mile per hour is 1.609344 kilometres per hour — the same pair of factors as distance, because speed is distance over time and the time unit does not change.

Common speed conversions

Common conversions, rounded to two decimal places: 50 km/h is 31.07 mph, 60 km/h is 37.28 mph, 80 km/h is 49.71 mph, 100 km/h is 62.14 mph, and 110 km/h is 68.35 mph. Going the other way, 30 mph is 48.28 km/h, 60 mph is 96.56 km/h, and 70 mph is 112.65 km/h. Use the converter for any other speed rather than estimating from this table, and remember that a converted speed is not a speed limit — always follow the limit posted on the road you are actually driving on.