Health Guide
How Much Water Should You Drink Per Day?
Daily water needs vary from person to person. Your body size, activity level, climate, sweat rate, diet, and caffeine or alcohol intake can all affect how much water you may need.
A simple starting point
A common everyday estimate is to start with about half your body weight in ounces of water per day. For example, a 180-pound person might use 90 ounces as a rough starting point.
That number is not perfect, but it gives you a simple baseline. From there, you can adjust based on exercise, heat, humidity, caffeine, alcohol, illness, or personal guidance from a health professional.
Try the free calculator
Use the Goodfolk Water Intake Calculator to estimate daily water intake based on weight, activity, weather, and caffeine or alcohol servings.
Open Water Intake CalculatorWhat affects water needs?
Body weight
Larger bodies generally need more total fluid than smaller bodies. That is why many quick hydration estimates start with body weight before adding adjustments for lifestyle and environment.
Activity level
Exercise increases sweat and breathing losses. Walking, running, strength training, hiking, outdoor work, and long travel days can all increase fluid needs.
Weather
Hot, humid, or dry conditions can increase how much water you lose. If you are sweating heavily or spending hours outside, you may need more than your usual daily amount.
Caffeine and alcohol
Coffee, tea, energy drinks, and alcohol can affect hydration habits. You do not always need to avoid them, but it can help to add extra water when those drinks are part of your day.
Signs you may need more fluid
Thirst, darker urine, dry mouth, headache, fatigue, dizziness, and reduced sweating during heat or exercise can be signs that you may need more fluids. Severe symptoms or ongoing concerns should be handled with medical guidance.
Bottom line
Start with a simple estimate, adjust for your day, and pay attention to how you feel. Your ideal water intake may change depending on weather, activity, travel, illness, and routine.