Awkward Internet speed

I've been watching tek syndicate for a long time but just recently join the forums and this seemed like the prefect place to ask this question. When i use a speed test for my internet speed it shows i have 50 mbps down and about 10 mbps up but when i download a file from a website or steam i get only 5 to 6.5 mbps. i am currently using a pci express wifi adapter card that is triple band 450mbps and i dont use a vpn. i also live in a densely populated sub urban area.  Any reply's would be very helpful. 

Internet speeds are usually listed in megabits per second (Mbps) from ISPs and speed tests. Steam, browsers, and other clients tend to display speeds in megabytes per second (MBps). 1 megabyte = 8 megabits. Most likely, this is just a misunderstanding for you, and you are receiving your advertised speeds.

+1

Advertised speeds = 50 Mbps

Websites and Steam downloading at 5 - 6.5 MBps

50 Mbps / 8 = 6.25 MBps....sounds about right.

Also where you are downloading from could be busy or have a bad connection or too far away etc.

Thanks for your help, I didnt know that.