# Does green tea count toward your water intake? Green tea counts in full, the same as water, and a cup carries about 30 mg of caffeine. Why the strength of your cup is mostly a brewing decision. ## Numbers the app uses | Field | Value | | --- | --- | | Default serving | 240 ml | | Hydration factor | 1.00 | | Counts toward the daily goal | 240 ml per serving | | Caffeine | 30 mg per serving | | Calories | 1 kcal per 100 ml (2 kcal per serving) | ## It counts, all of it A 240 ml cup of green tea adds 240 ml to the goal. Its hydration factor is 1.00, identical to water, and that is not a courtesy. Researchers measured how much of a range of everyday drinks the body retained. Tea sat in the same group as still water. The trial is cited at the foot of this page. Tea is water with a small amount of caffeine and a trace of dissolved leaf in it. And 30 mg is nowhere near the dose where the mild diuretic effect starts to matter. ## A third of a coffee's caffeine Thirty milligrams is about a third of what a 240 ml cup of black coffee delivers and under half an espresso shot. Four cups spread across a day come to 120 mg, barely more than one cup of black coffee on its own. This is why green tea works as the afternoon drink when the caffeine budget has run out. The app's coffee deadline may have closed hours ago. A cup of green tea will often still fit under it. ## The strength of your cup is a brewing decision Green tea is unusual in how much the number depends on you rather than on the leaf. Water temperature and steep time move the caffeine more than the quantity of leaf does. One minute at 70 °C pulls out far less than three minutes at 90 °C from the same spoonful. The 30 mg here is a middle-of-the-road cup. Yours may be reliably stronger or weaker, say a long-steeped sencha or a genmaicha cut with rice. If so, save a custom drink in the app with your own caffeine figure. Anything decaffeinated gets logged with the *Caffeine-free* switch. ## Source Hydration factors follow the Beverage Hydration Index. Maughan RJ, Watson P, Cordery PA, et al. “A randomized trial to assess the potential of different beverages to affect hydration status: development of a beverage hydration index.” American Journal of Clinical Nutrition, 2016;103(3):717-723. https://pubmed.ncbi.nlm.nih.gov/26702122/ Page: https://waterchamp.app/drinks/green-tea/