Ticket prices for riding on the Metro, and indeed for other forms of public transport in Dubai are calculated based on the Dubai Metro Zones in which you travel, which can get a little bit complicated.
At the time of writing, the number of zones that Dubai is split into is 7 but 3 of these are outside the Dubai Metro area. Zones 3, 4 and 7 contain other areas of public transport, including buses. Zones 1, 2, 5 and 6 are zones that contain Dubai Metro stations. Therefore, if you take a bus after taking the Dubai Metro then you may need to take account of the extra zones when calculating your fare for that journey.
Fares are calculated according to the number of zones that you travel through and not the difference in the numbers of the zones. For example, if you go from Mall of the Emirates Metro station in Zone 2 to Dubai Mall/Burj Khalifa station in Zone 6 that is counted as 2 zones as you have only travelled through Zones 2 and 6, it does not mean that you have travelled through 4 zones as the other zones are not on your route.
However, if you travel from Damac to Mall of the Emirates and then get a bus (within 30 minutes) to Arabian Ranches then not only will you travel within Zone 2 on the metro, but also you will travel in Zone 3 on the bus so that would mean you would travel through 2 zones.
In order to have the correct fare calculated, you need to swipe in and out on every mode of transport that you use, otherwise you will be charged the maximum fare for your journey (or possibly for each journey if you use more than one mode of transport). The maximum fare on a silver Nol card for one journey is 7.5 dirhams which is why you always need to have this amount loaded on your Nol card before you travel. The maximum fare on other Nol cards may be different so check the tickets page for more info.
You can check out all of the travel zones on the RTA website and if you then know how many zones you will be travelling through you can calculate the price of the ticket by checking out the tickets page.
There are also different ticket prices for season tickets which depend on the number of zones that you travel through.
You can check out the zones that are covered by the Dubai Metro, plus each of the stations that are in each zone, in the map shown below.
