One of the easiest and surest ways to calculate the distance between two cities is to use an online distance calculator that is built from reliable sources. One website that offers this service is distancecalculator.net.
This website application uses both Google Maps API and the GeoNames country and city database, which has more than 8 million place names registered as of 2015. The app gives results both as road distances and air distances and is built on a bootstrap responsive framework, which means you can view it equally on a desktop computer, laptop, tablet or a smartphone. It also gives you the option of viewing the distance in kilometers, miles or meters.