A According to the National Coffee Association, one pound of coffee brews about 45 cups (a cup being 6 oz.). But who drinks only 6 ounces of coffee… so I always say 22 mugs of coffee per lb.
You can use this calculator to figure out how much coffee you need in a month! Very handy
But then this is really a guideline but it does depend on how strong you like your brew. The most basic way to measure coffee to water is 2 Tbsp to every 6 oz. of water and adjust from there.