Maximum download and upload speeds?
Translated to: Speed (KBps)
128 = 16
256 = 32
384 = 48
768 = 96
1000 = 125
1500 = 187.5
2000 = 250
3000 = 375
7100 = 887.5
The speeds above are the same factor for Upload as well. It's worth noting that some of your bandwith is eaten up by packet headers. Your upload and download speed are dependent upon each other, so if you use a lot of upload it can affect your download speed.
Note: 1 Kilobyte = 8 Kilobits.
Or, To calculate kilobits from kilobytes, "multiply" by 8. Example: 1 Kilobyte = 8 kilobits
What's this mean to me?
In the image above, the download speed is indicated in KBps. Using the chart, that translates to an actual download speed of around 1250 kbps, or 1.25 megabits.
For example: 1500 Downstream is equal to 1500/8 (1500 divided by 8) Which gives you 187.5KBps maximum downstream. Reaching That speed with a 1.5Mbps connection (1500kbps) is theoretically minimal, although you may come close.