Drink hydration chart: what counts as water

Yes. Coffee is mostly water, and in the Beverage Hydration Index study (Maughan et al., American Journal of Clinical Nutrition, 2016) it hydrated about as well as water at the amount tested. Waltermelon counts coffee at 98%, so a 12 oz cup adds about 11.8 oz to your daily water goal. Coffee is free to log in Waltermelon.

Most of them. Water, sparkling water, tea, coffee, milk, juice, sports drinks and even soda all add to your daily total in Waltermelon, each at its own hydration value. Alcoholic drinks are the exception: beer, wine, champagne and spirits lower your total in Waltermelon instead.

In the Beverage Hydration Index study (Maughan et al., 2016), whole milk, skim milk and an oral rehydration solution kept the most fluid in the body, about 1.5 times as much as water two hours later. In Waltermelon, milk counts at 120%, and so do sports drinks, for their electrolytes, even though the sports drink in the study came out close to water. Lattes and non-alcoholic beer count at 110%, cappuccino at 105% and juice at 102%.

In research, yes. In the Beverage Hydration Index study, milk stayed in the body longer than the same amount of water, likely because its protein, fat and electrolytes slow fluid loss. Waltermelon counts milk at 120%, so an 8 oz glass adds 9.6 oz to your water goal.

Less than it seems. In the Beverage Hydration Index study, a regular lager hydrated about as well as water at the amount tested, but the alcohol in it still makes you pee a bit more than an alcohol-free beer would, and stronger drinks raise the effect. Waltermelon plays it safe and counts beer at -39%, so a 12 oz can lowers your total by about 4.7 oz, as a nudge to drink a glass of water with it. Non-alcoholic beer counts at 110%.

Alcohol makes your body let go of more water than usual, and the effect grows with strength. Waltermelon counts beer at -39%, champagne at -87%, wine at -95% and spirits at -360%, so a 1.5 oz shot takes about 5.4 oz off your day. It is a simplified tracking value, not a lab measurement.

Yes. Tea is mostly water, and in the Beverage Hydration Index study it hydrated about as well as water. Waltermelon counts tea at 95% and green tea at 96%, and tea is free to log.

The Beverage Hydration Index is a measure from a 2016 study by Ronald Maughan and colleagues in the American Journal of Clinical Nutrition. 72 men drank 1 liter of a test drink on separate days (water plus up to three of the 13 drinks), and the index compares how much fluid stayed in the body two hours later against water (water = 1). Whole milk, skim milk and an oral rehydration solution scored highest, about 1.5; coffee, tea, cola, sparkling water, a sports drink and lager were similar to water. Orange juice also scored above water at two hours, but not once its lower water content was taken into account. Waltermelon’s drink values are informed by research like this.

Yes. The National Academies estimate that about 20% of the water people take in comes from food, such as fruit, vegetables and soup. Waltermelon tracks what you drink, not what you eat, so the water in your meals comes on top of the total you log.

Yes. With Waltermelon Premium you can type any drink, like an oat milk latte or a specific brand, and the AI estimates its hydration value, caffeine and sugar. Premium also lets you create custom drinks with your own values. Free users get a few AI tries.