Command to take average time-to-first-byte for a given URL

ttfb.sh

#!/usr/local/bin/bash

 total=0.000
 ttfbs=()

 for i in `seq 1 5`
 do
     ttfb=$(curl -s -o /dev/null -w "%{time_starttransfer}" "$1")
     total=$(scale=3;echo "$total+$ttfb" | bc)
 done

 average=$(scale=3;printf %.2f $(echo "$total/5" | bc -l))

 echo "Average TTFB for 5 attempts is: $average"