Most of us turn to the quick relief of coffee when we’re dragging. As it turns out, not every cup has the same amount of that pick-me-up.

According to the experts, several factors determine how much caffeine will be extracted from the beans including the roast, grind size, brew time, temperature and style.
While you may believe a darker roast contains more of the drug since it tastes stronger, that’s not the case. “Blonde” roasts actually have more caffeine, according to doctors quoted by Readers Digest.

In general, a brewed cup of Joe has around 95mg of caffeine. Espresso works out to about 63mg on average and instant clocks in between 65 and 80mg.