Some routers report the traffic volume, though off-hand I don't know which. Logging it daily is a chore, but feasible, because I did it when I first went to a limited allowance package.
Otherwise you need one that supports SNMP, or something like PRTG
My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost
. Internet connection -
IDNet Home Starter Fibre. Live BQM
"Where talent is a dwarf, self-esteem is a giant."
- Jean-Antoine Petit-Senn.