… drink more coffee! In a study released April 21, 2017 by ScienceDirect, it was determined to be safe for healthy adults to consume up to 400 mg of caffeine per day. Pregnant women should limit to under 300 mg per day. For children, they should keep their consumption to less than 2.5 mg per kg of weight per day. For us Americans, that would be approximately 1.14 mg per lb weight.
The problem is, there is a large gap in how much caffeine is in a cup. Brewed coffee has about 95-165 mg per 8 oz. cup. As a rule of thumb, if you measure the amount of cofee, each 10 grams of Arabica coffee has about 100 mg caffeine. So no matter how you brew, that amount of beans will yield no more than that much caffeine. Somebody from coffee.stackexchange.com did the research for this. This is not an entirely conclusive way to measure. Someone later on this page does say you would need to send about 4 samples of coffee brewed the same way from different batches to a testing facility to see what is really in your brews.
Just know it’s safe to drink about 4 cups coffee per day!