What a hydration factor is
A hydration factor is a multiplier on the volume you drink, and it does two things. It scales how far the drink moves the hydration level on the home screen. When the factor is below 1.0, the app adds the missing millilitres to the day's goal. The factor never takes anything away. The goal counts every millilitre you logged, at face value.
Log 250 ml of water, factor 1.0. The full 250 ml counts toward the goal, and the goal stays where it was. Log 250 ml of milk, factor 1.5. The 250 ml still counts, but the hydration level rises half again as far as water would move it. More of that fluid stays in the body over the next few hours. A 150 ml glass of red wine, factor 0.5, also counts as the full 150 ml. It adds 75 ml to the goal on top. Spirits sit at 0.0, so a 45 ml measure counts as 45 ml and adds another 45 ml to the goal.
The ordering comes from the Beverage Hydration Index. Maughan and colleagues gave 72 men one litre of each of 13 drinks. They measured urine output for the next four hours and scored every drink against still water. 1 Milk, an oral rehydration solution and orange juice held onto more fluid than water did. Tea, coffee, cola, a sports drink, sparkling water and beer came out no different from water. The mechanism is plain. Energy density, sodium and protein slow how fast the stomach empties. The same volume then arrives at the kidneys more slowly, and less of it leaves again straight away.
The study covered 13 drinks and the app carries 62. We place the rest by category against their measured neighbours. A smoothie sits near milk because it is thick and carries protein and sugar. A plain herbal infusion sits on water. Alcohol is the one direction that goes below 1.0. Alcohol suppresses vasopressin, so you pass more urine than the drink supplied. Treat the factors as a careful ranking, not a lab measurement for each drink.
A factor above 1.0 is not a health score. Chocolate milk retains fluid well, at 1.45, and it also carries 63 kcal per 100 ml. The table below keeps the calories next to the factor for exactly that reason.
All 62 drinks
Click a heading to sort by that column. Click it again to reverse the order. The number columns start with the highest value; Drink and Category start at A. The search box filters by drink name or category. Serving is the amount the app offers first, and you can change it before you log. Caffeine is the amount in that serving. For coffee and tea the app counts shots and cups, so a taller cup of the same brew keeps the same caffeine. Sodas, energy drinks and cold brew scale with volume. Calories are given per 100 ml rather than per serving, so drinks of very different sizes stay comparable. Alcohol is alcohol by volume. The app converts it to grams of pure alcohol at 0.789 g/ml.
62 drinks
| Affogato | Coffee | 150 ml | 1.0 | 63 mg | 120 kcal | – |
|---|---|---|---|---|---|---|
| Almond Milk | Dairy | 250 ml | 1.0 | – | 15 kcal | – |
| Americano | Coffee | 240 ml | 1.0 | 63 mg | 2 kcal | – |
| Aperol Spritz | Alcohol | 200 ml | 0.5 | – | 65 kcal | 8% |
| Apple Juice | Juice | 200 ml | 1.05 | – | 46 kcal | – |
| Beer | Alcohol | 500 ml | 1.0 | – | 43 kcal | 5% |
| Berry Juice | Juice | 200 ml | 1.05 | – | 48 kcal | – |
| Black Coffee | Coffee | 240 ml | 1.0 | 95 mg | 1 kcal | – |
| Black Tea | Tea | 240 ml | 1.0 | 47 mg | 1 kcal | – |
| Boba Tea | Tea | 475 ml | 1.1 | 40 mg | 65 kcal | – |
| Cappuccino | Coffee | 200 ml | 1.1 | 63 mg | 30 kcal | – |
| Chai Latte | Tea | 350 ml | 1.1 | 50 mg | 45 kcal | – |
| Chocolate Milk | Dairy | 250 ml | 1.45 | – | 63 kcal | – |
| Cider | Alcohol | 500 ml | 1.0 | – | 46 kcal | 4.5% |
| Coconut Water | Water | 330 ml | 1.05 | – | 19 kcal | – |
| Cola | Soft drink | 330 ml | 1.0 | 34 mg | 42 kcal | – |
| Cold Brew | Coffee | 350 ml | 1.0 | 200 mg | 2 kcal | – |
| Cortado | Coffee | 120 ml | 1.05 | 63 mg | 18 kcal | – |
| Diet Soda | Soft drink | 355 ml | 1.0 | 46 mg | 0 kcal | – |
| Drip Coffee | Coffee | 355 ml | 1.0 | 95 mg | 1 kcal | – |
| Energy Drink | Soft drink | 250 ml | 1.0 | 80 mg | 45 kcal | – |
| Espresso | Coffee | 40 ml | 1.0 | 63 mg | 2 kcal | – |
| Flavored Water | Water | 500 ml | 1.0 | – | 5 kcal | – |
| Ginger Beer | Soft drink | 330 ml | 1.0 | – | 35 kcal | – |
| Grape Juice | Juice | 200 ml | 1.05 | – | 60 kcal | – |
| Green Juice | Juice | 300 ml | 1.05 | – | 34 kcal | – |
| Green Tea | Tea | 240 ml | 1.0 | 30 mg | 1 kcal | – |
| Herbal Infusion | Tea | 240 ml | 1.0 | – | 1 kcal | – |
| Hot Chocolate | Dairy | 240 ml | 1.35 | – | 70 kcal | – |
| Iced Coffee | Coffee | 475 ml | 1.0 | 95 mg | 5 kcal | – |
| Iced Tea | Tea | 355 ml | 1.0 | 17 mg | 36 kcal | – |
| Irish Coffee | Alcohol | 240 ml | 0.5 | 95 mg | 95 kcal | 10% |
| Isotonic Drink | Soft drink | 500 ml | 1.05 | – | 25 kcal | – |
| Juice | Juice | 200 ml | 1.05 | – | 45 kcal | – |
| Kefir | Dairy | 250 ml | 1.4 | – | 60 kcal | – |
| Kiwi Smoothie | Smoothie | 300 ml | 1.2 | – | 48 kcal | – |
| Kombucha | Tea | 330 ml | 1.0 | – | 15 kcal | – |
| Latte | Coffee | 350 ml | 1.1 | 63 mg | 42 kcal | – |
| Lemon-Lime Soda | Soft drink | 330 ml | 1.0 | – | 42 kcal | – |
| Lemonade | Soft drink | 300 ml | 1.0 | – | 42 kcal | – |
| Margarita | Alcohol | 240 ml | 0.5 | – | 100 kcal | 13% |
| Martini | Alcohol | 90 ml | 0.0 | – | 150 kcal | 25% |
| Matcha Latte | Tea | 350 ml | 1.1 | 70 mg | 30 kcal | – |
| Milk | Dairy | 250 ml | 1.5 | – | 42 kcal | – |
| Mojito | Alcohol | 240 ml | 0.5 | – | 60 kcal | 10% |
| Oat Milk | Dairy | 250 ml | 1.05 | – | 48 kcal | – |
| Orange Juice | Juice | 200 ml | 1.1 | – | 45 kcal | – |
| Prosecco | Alcohol | 125 ml | 0.5 | – | 66 kcal | 11% |
| Protein Shake | Smoothie | 330 ml | 1.3 | – | 65 kcal | – |
| Red Wine | Alcohol | 150 ml | 0.5 | – | 85 kcal | 13.5% |
| Root Beer | Soft drink | 330 ml | 1.0 | – | 43 kcal | – |
| Rosé Wine | Alcohol | 150 ml | 0.5 | – | 80 kcal | 12% |
| Slushie | Soft drink | 475 ml | 1.0 | – | 48 kcal | – |
| Smoothie | Smoothie | 300 ml | 1.2 | – | 55 kcal | – |
| Soda | Soft drink | 330 ml | 1.0 | 34 mg | 42 kcal | – |
| Sparkling Water | Water | 330 ml | 1.0 | – | 0 kcal | – |
| Spirit | Alcohol | 45 ml | 0.0 | – | 231 kcal | 40% |
| Strawberry Smoothie | Smoothie | 300 ml | 1.2 | – | 50 kcal | – |
| Turmeric Latte | Tea | 240 ml | 1.1 | – | 25 kcal | – |
| Water | Water | 250 ml | 1.0 | – | 0 kcal | – |
| Wellness Shot | Juice | 60 ml | 1.0 | – | 30 kcal | – |
| White Wine | Alcohol | 150 ml | 0.5 | – | 82 kcal | 12.5% |
No drink matches that search.
Reading the hydration column
Most of the table sits at 1.0. That is the measured result for tea, coffee, soda and beer. Over a few hours they leave you about where water would have. The ends of the table are the useful rows. Milk at 1.5, chocolate milk at 1.45 and kefir at 1.4 are the only drinks that beat water by a wide margin. Smoothies and protein shakes follow at 1.2 to 1.3. Every alcoholic drink except beer and cider drops to 0.5. Neat spirits and a martini fall to 0.0. A 45 ml measure of spirit does nothing for your hydration level. It adds its own 45 ml to the day's goal, and it still carries 104 kcal.
The app applies the factor as you log, so the hydration level on the home screen already accounts for it. Nothing here is a limit or a warning. It is arithmetic on what you drank. You can change any drink's factor if you disagree with ours.
1. Maughan RJ, Watson P, Cordery PA, Walsh NP, Oliver SJ, Dolci A, Rodriguez-Sanchez N, Galloway SDR. “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. PubMed 26702122. Serving sizes, caffeine, calorie and alcohol figures are the defaults shipped in the app.
