Yes, or at least very close. Coffee, as I am sure you know from making it or watching it being made, is almost all water and it enters the body just like a glass of water. No one advises you to take all your daily fluid requirements through a coffee drink but at the end of the day the water from those drinks counts towards your fluid total and helps hydrate you. Drinking large amounts of caffeinated drinks can cause you to urinate more often in order to remove excess caffeine but it’s only a matter of putting it back when you get thirsty (just like when you drink lots of water frequently, you urinate more). It is a long-standing myth that coffee or tea lead to a net water loss. Enjoy your coffee and count it in your daily fluid needs. Fluid requirements for healthy sedentary adults living in temperate climates are as follows: Men 125 oz (~3qts) of water per day from all dietary sources; Women 91 oz (~2qts) of water per day from all dietary sources. About 20% of your fluid requirements will come from foods you eat. Athletes and exercisers need more.