Windows 10 includes a built-in network usage monitor which shows you the bandwidth consumed by all your apps over the last 30 days.
If you've never noticed the monitor before, you're not alone-- it's easy to miss. Launch the Settings app, click Network and Internet > Data Usage > View Usage Details for the breakdown.
This works well, but the system gives you no control over the data usage period. It's always the last 30 days, annoying if - for instance - you want to measure your usage over the current month.
Reset Data Usage is a tiny portable tool which can reset your usage counts to zero whenever you like.
The program doesn't have a manual, but then you won't need one. Clearing your stats is as simple as launching the program and hitting "Reset Data Usage".
Alternatively, using a /R switch from the command line enables resetting the counts from a script. Use this from a scheduled task and you could automatically reset usage stats every day, week, month, whenever works for you.