# Water Intake Calculator > How much water should you drink per day? Based on body weight, activity level, climate, and pregnancy or lactation status. URL: https://uttir.com/water-intake-calculator Categories: calculators Privacy: All math runs locally. No data leaves your browser. ## About A common rule of thumb is 8 cups (about 2 L) per day, but the actual number varies with body size, activity, climate, and life stage. The most cited evidence-based model is 30-35 ml per kg of body weight, which scales to the person's size. Add a bonus for hot climate (+200-500 ml) and for pregnancy (+300 ml) or lactation (+700 ml). This calculator returns the result in four units so you can use whichever you prefer: litres, millilitres, US fluid ounces, and the 8-oz (240 ml) cup. The "baseline" is the body-weight × factor number; the adjustments are listed separately so you can see what each part contributes. ## How to use 1. **Enter your body weight** — In kilograms. Convert from pounds by dividing by 2.205. 2. **Pick your activity level** — Be honest. A desk job is "sedentary"; a construction worker is "very active". 3. **Pick your climate** — Most people are "temperate". If you live in a hot or humid place, use "hot". 4. **Set pregnancy or lactation** — Adds 300 ml/day for pregnancy, 700 ml/day for lactation. ## Examples ### 70 kg adult, moderate activity, temperate A typical office worker who exercises 3-4 times a week. Output: ``` ~2.3 L/day, ~9 cups of 8 oz ``` ### 80 kg adult, very active, hot climate A construction worker in summer. Output: ``` ~3.9 L/day, ~16 cups of 8 oz ``` ## FAQ ### Does coffee, tea, and food count? About 20-30% of your daily water intake comes from food (especially fruits, vegetables, and soups). Caffeinated drinks count toward your total — caffeine is a mild diuretic but the water in coffee more than offsets it for typical intakes. The 2-3 L/day target is total water from all sources, not just what you drink. ### Can I drink too much water? Yes, in rare cases. Hyponatremia (low blood sodium from over-dilution) is mostly a concern for endurance athletes who drink huge amounts during long events without replacing electrolytes. For most people, drinking to thirst and matching the calculator's recommendation is safe. If you have kidney or heart conditions that require fluid restriction, follow your doctor's limit, not this tool. ### How do I know if I am drinking enough? Urine colour is the simplest check. Aim for pale yellow (like lemonade) throughout the day. Dark yellow or amber means you are under-hydrated; completely clear means you are well-hydrated or possibly over-hydrated. Thirst is a lagging signal — by the time you feel thirsty, you are already 1-2% dehydrated. ## Related tools - [BMI Calculator](https://uttir.com/bmi-calculator) — Calculate your Body Mass Index and see where you fall on the healthy range. - [Calorie Calculator (BMR + TDEE)](https://uttir.com/calorie-calculator) — Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE). Includes a goal-adjusted daily calorie target. - [Macro Calculator](https://uttir.com/macro-calculator) — Calculate daily protein, carb, and fat grams from a calorie target. Four common splits: balanced, high-protein, low-carb, and keto. - [Body Fat Calculator](https://uttir.com/body-fat-calculator) — Estimate body fat percentage using the U.S. Navy circumference method. Tape measure and a few seconds — no scales required. - [Ideal Weight Calculator](https://uttir.com/ideal-weight-calculator) — Calculate your ideal body weight using four clinical formulas (Devine, Robinson, Miller, Hamwi) plus a healthy BMI range. --- For the full HTML page with the live tool, visit https://uttir.com/water-intake-calculator. This file is the markdown rendering at https://uttir.com/water-intake-calculator.md. See https://uttir.com/llms.txt for a site-wide summary.