無料オンライン水分摂取量計算機

General guidelines: men need about 3.7 liters (125 oz / 15.5 cups) total daily water; women need 2.7 liters (91 oz / 11.5 cups). About 20% comes from food. Individual needs vary by body size, activity, climate, and health status.

Yes. Despite being mild diuretics, caffeinated beverages (coffee, tea) still net positive hydration — the water they contain outweighs the mild diuretic effect. Only very high caffeine doses approach neutrality.

Dark yellow urine (target pale yellow), thirst (you're already slightly dehydrated when thirsty), headache, fatigue, decreased focus, and dry mouth. 2% dehydration measurably reduces cognitive and physical performance.

Drinking water before meals reduces caloric intake by increasing fullness. Cold water may slightly boost metabolism. However, water itself doesn't cause fat loss — it supports overall health and can aid adherence to a calorie deficit.

Yes. Hyponatremia (water intoxication) occurs when you drink so much water that blood sodium becomes dangerously diluted. It's rare but occurs in endurance athletes who over-drink plain water during long events. Electrolytes are needed alongside high water intake.

Yes, the 水分摂取量計算機 on Allio Tools is completely free with no sign-up or registration required. It works directly in your browser.

体重と活動量に基づいて1日に飲むべき水の量を計算します。 No data is sent to a server — everything runs locally in your browser for maximum privacy and speed.

No installation needed. The 水分摂取量計算機 runs entirely in your web browser on any device — desktop, tablet, or mobile.

Completely safe. The 水分摂取量計算機 processes everything locally in your browser. No input data, results, or usage information is ever transmitted to or stored on any server.

After the page loads for the first time, the 水分摂取量計算機 works without an internet connection for all client-side processing. Tools that fetch live external data (such as DNS or network lookups) require an active connection.

The 水分摂取量計算機 uses clinically validated formulas such as the Mifflin–St Jeor or Harris–Benedict equations where applicable. Results are population-based estimates and can differ from measured values by 10–20% for individuals with atypical body composition. See our <a href="/methodology/">Methodology page</a> for full formula sources and references. Consult a qualified healthcare professional before making medical or dietary decisions.

The 水分摂取量計算機 uses an established, peer-reviewed formula endorsed by leading health organisations such as the WHO, CDC, or NIH where applicable. The specific formula is chosen for its validated accuracy across diverse adult populations under normal conditions.

Yes. The 水分摂取量計算機 is built with standard browser APIs and works on all modern browsers including Chrome, Firefox, Safari, and Edge — on both desktop and mobile. No plugins, extensions, or third-party software are required.

Select and copy the result text to paste into any document or app. For image tools, a Download button saves the file directly to your device. Your browser's built-in screenshot function also captures results quickly. No account or login is required.