How big of a pipe do I need?

fibre feed estimate bandwidth

[wheel]

Is there any way to estimate how big of a feed I need to host my own servers? I would also welcome general opinions.

I have many low traffic sites, and one mid to high traffic site. The high traffic site runs a phpBB bulletin board that sees 75 people on it at any given time (and at certain times of the year can go as high as 120). This site would account for 80% of the traffic on the server(s). It uses 15-30 gigs of transfer per month.

My ISP has two plans - 2mbits sustained/4 burstable and 4mbits sustained/10 burstable. I'm concerned that the 2mbit plan will result in noticeable slowdown.

[daisho]

You should be fine. I run a network that has a full T (1.54 Mbits) and we in total run about 25,000 uniques a day plus office internet access and we still have some room. Although it will depend on the type of content that you send.

[Brett_Tabke]

You've have looked at your peak hour for the day, added up the bytes and divided by the total requests for that hour? That would give you a good idea of your current bandwidth needs.

[wheel]

Thank you *very* much for the responses. Exactly what I need.

Almost all the traffic is html/text as the pages I host are very tight with minimal graphics. So I don't expect a problem there.

My busiest hour seems to have about 50,000K in the hour. I figured a 2mbit connection should do:
2mbit per second / 8bits/byte=250K/second
* 60seconds/minute * 60minutes/hour=900,000K per hour.

Which means I'm well in the ballpark. Does that seem right?