Double sized mug when I get up, followed by another. Various mugs throughout the day, quite often nip into trade counters to pick up just a coffee, customers provide coffee continuously. But they're free, so I'm not counting them. Maybe a couple if I nip home to pick anything up. Evenings, continuous coffee, so yes, easy 10 to 20 a day. Maybe cost more if I'm home in the day, and paying for my own. Coffee holder in the car always has a cup in it. The kids bought me a thermal mug for christmas. I bought my last car on condition it had a coffee holder.
I'm also an insomniac, so my last cup is about 1 to 2 am.
I did switch to decaf though.