Handy dandy tool to go with it: http://www.aqwnet.com/index.php/tools/ip-mac-calculator (courtisy AQW lenowo tool)
for instance this 244.0.0.22.
Multicast IP 224.0.0.22 converts to:
MAC address 01:00:5e:00:00:16
Matched multicast IP group addresses
224.0.0.22
224.128.0.22
225.0.0.22
225.128.0.22
226.0.0.22
226.128.0.22
227.0.0.22
227.128.0.22
228.0.0.22
228.128.0.22
229.0.0.22
229.128.0.22
230.0.0.22
230.128.0.22
231.0.0.22
231.128.0.22
232.0.0.22
232.128.0.22
233.0.0.22
233.128.0.22
234.0.0.22
234.128.0.22
235.0.0.22
235.128.0.22
236.0.0.22
236.128.0.22
237.0.0.22
237.128.0.22
238.0.0.22
238.128.0.22
239.0.0.22
239.128.0.22
pol