Divide by Seconds in Time Picker?

Can I make a column that is a sum divided by time range up right?

For example, I have one column that is a top 10 by bytes transferred. I want to display the mbit/sec for the host beside it. I can pre-do some of the math in logstash via ruby if necessary (bytes to bits, etc) but I can't figure out how to take the value and divide it by whatever time is picked. I don't really want the average - there may be hundreds of thousands of packets, so the average size in bytes isn't what I want. I want to make a bytes/time column, where /time is based on the number of seconds in the time picker.

This is not supported in Kibana today, but we have an open issue for this kind of metric math: https://github.com/elastic/kibana/issues/4646#issuecomment-130338994