I know to convert bytes to KB we divide by 1024 and then to convert it to MB we divide again by 1024.
Correct we if i am wrong is there any other easy way that we can do this
Not really no. That is the standard way to do it. You can get close by diving by 1000 rather than 1024 which is easier to do in your head.
Also bear in mind with networking we talk about bits not bytes so you must remember that 100Mbps = 100Megabits so you need to divide by 8 to get to bytes.