以下详细说明暂以英文提供。
Where the numbers come from
The baseline of roughly 35 milliliters per kilogram of body weight is a long-standing clinical rule of thumb for adult fluid needs — about 2.5 liters for a 70 kg person before any exercise. Movement adds to it at around 12 ml per half hour of activity to cover sweat, and hot or humid weather multiplies the whole target by 15% because you lose more to perspiration even at rest. No formula beats your own signals, but this lands close to where dietitians start.
Reading the result
The target covers all fluid, not just plain water: coffee, tea, milk, and the roughly 20% of fluid that arrives in food all count, so the glass count is a ceiling of dedicated water drinking rather than a quota. Spread intake across the day, front-load a glass on waking, and let urine color be the daily check — pale straw means you are on track, dark amber means drink up.
中国本地参考
日常计算时值得知道的中国本地规则：
- 计量的单位习惯: 住房面积用平方米，土地常用亩（1 亩 ≈ 666.7 平方米）；里程用公里，油耗用 L/100km。
- 日期与数字格式: 日期写作 2026年10月13日（年-月-日）；大数习惯用万、亿（1 万 = 10,000，1 亿 = 100,000,000）。
- 法定节假日: 全年法定节假日 11 天，春节与国庆为长假；调休安排每年由国务院办公厅发布。
- 速度与限速: 高速公路最高限速 120 km/h，城市快速路多为 80 km/h，均以公里每小时计。
- 鞋服尺码: 鞋码用中国码（毫米制），服装常用 155/80A 这类身高围度组合，与欧美码不同。
数据核对：2026 年 10 月
常见问题
Is more always better?
No. Healthy kidneys shed a couple of glasses an hour at most, and forcing far beyond thirst can dilute blood sodium — a rare but real condition. People with kidney or heart conditions should follow the intake their care team sets.
Does coffee dehydrate me?
The mild diuretic effect is small and fades with regular drinking, so coffee and tea still contribute positively to your daily total. The old rule that caffeinated drinks do not count has been retired by the research.
Is this medical advice?
No — it is a population-level estimate. Pregnancy, kidney disease, certain medications, and endurance training all change real needs, so treat the result as a starting point and defer to your clinician.