No, the time will depend on various things e.g. Your table size (MB), Disk I/O speed, memory, sort buffers, CPU, etc.
Best is to build an index on a sample to get an estimate e.g.
select top 10000 * into sampletable from largetable
Then build an index on sampletable
If it takes 10 second then you can guess that 5000000
will take 10*500=5000 seconds
You can also look at the size of the table (data KB from sp_spaceused)
If another_large_table is twice as big then it should take twice as long
Note: Clustered (placement) indexes take much longer as all the data is copied to a new location.