Daily Water Intake Calculator
Get your personalized daily water target — and a bottle size that makes hitting it realistic.
Body weight
Activity level
Climate
Your daily intake target
Daily water
96oz
2.8 L · 2839 mL
Recommended bottle size
32oz
2-3 refills covers your day. Smaller bottles for portability; larger if refills are inconvenient.
Bottles close to 32oz
Contigo
Contigo West Loop 3.0 Stainless Steel Insulated Travel Mug, Leak Proof with AutoSeal Lid, 24oz, Matte Black
YETI
YETI Rambler 20 oz Tumbler, Stainless Steel, Vacuum Insulated with MagSlider Lid, Navy
YETI
YETI Rambler 20 oz Tumbler, Stainless Steel, Vacuum Insulated with MagSlider Lid, Black
YETI
YETI Rambler 20 oz Tumbler, Stainless Steel, Vacuum Insulated with MagSlider Lid, Stainless
How this works
Is "half your body weight in ounces" really right?
It's a sensible mid-range heuristic. Real needs depend on activity, climate, body composition, and individual physiology. Most healthy adults land within ±25% of this number.
Does coffee count toward my intake?
Yes — modest amounts of caffeine don't cause net dehydration. Coffee, tea, sparkling water, soup, and watery fruits all count toward your daily fluid total.
What size bottle is right for me?
Aim for 2-3 refills per day. 24oz works for sedentary days; 32oz is a sweet spot for moderate activity; 40oz+ if refilling is inconvenient (long meetings, travel days). Larger bottles encourage drinking more.
Why does climate matter so much?
You lose 8-16oz/hour through sweat in hot or dry conditions, even without intense exercise. High altitude also accelerates fluid loss through respiration. Both add 12-20oz to baseline needs.