How Much Bandwidth Does VoIP Use? Posted on by Webmaster IT Support Forum › Forums › Telephony › General Discussion › How Much Bandwidth Does VoIP Use? Tagged: Bandwidth, VoIP This topic contains 0 replies, has 1 voice, and was last updated by Webmaster 2 years, 6 months ago. Author Posts December 3, 2015 at 11:09 am #1479 WebmasterKeymaster Want to know how much bandwidth VoIP uses? VoIP uses about 90Kb/s per VoIP phone. So if you have 10 phones, you’ll need 900Kb/s available. Author Posts You must be logged in to reply to this topic.