For low-carb and keto
Keto Water Intake Calculator
Quick answer
WaterDailyGoal uses 33 ml/kg for a beverage planning estimate. The 30–40 ml/kg scenarios and activity/climate coefficients are site assumptions, not validated personal requirements or NAM/EFSA formulas. Electrolytes are not automatic. Long or heavy sweating and vomiting or diarrhea need different approaches; food, losses and medical restrictions matter. Ask a clinician or pharmacist when illness is involved.
Fine-tuneMeasure in bottles · Your day
Saved profile
Save this setup to resume tomorrow on this browser.
Your daily goal: 3.1 Litres, 12.5 glasses.
Your daily goal
Updates instantlyof water a day · about 12.5 glasses · 6 half-litre bottles
Planning scenarios: 2.9-3.7 Litres. Use it as a flexible target, not a medical limit.
Start
2 glasses
7:00 AM
Taper
9:00 PM
for better sleep.
Food fluid
+0.8 L
typical food water
- 3.1
- Litres
- 105
- Ounces
- 12.5
- glasses
Why this number
WaterDailyGoal uses 33 ml/kg for a beverage planning estimate. The 30–40 ml/kg scenarios and activity/climate coefficients are site assumptions, not validated personal requirements or NAM/EFSA formulas. Pregnancy, breastfeeding, and GLP-1 medicines do not automatically change this estimate. Population total-water references include food; they are not minimum drinking doses. Follow individual clinical advice.
Full methodologyNext step
Your sip schedule
- 7:00 AM · Start the day2 glasses
- 9:48 AM · Top up2 glasses
- 12:36 PM · Top up2 glasses
- 3:24 PM · Top up2 glasses
- 6:12 PM · Top up2 glasses
- 9:00 PM · Wind down2.4 glasses
Ease off after 9:00 PM for better sleep.
Electrolytes? Not automatic
Electrolytes are not automatic. Long or heavy sweating and vomiting or diarrhea need different approaches; food, losses and medical restrictions matter. Ask a clinician or pharmacist when illness is involved.
A friendly estimate for healthy adults, not medical advice. Your needs rise with heat, exercise, illness, pregnancy, and some medications. Don't drink more than ~1 litre per hour.
Your daily goal
3.1 Litres
The link and preview image include your weight and settings.
Why keto changes hydration
Low-carb diets reduce glycogen stores. Because glycogen carries water with it, the first visible weight drop on keto is often mostly water.
That water carries electrolytes too, especially sodium. This is why early keto can feel like headache, fatigue, lightheadedness, or cramps.
Water plus careful electrolytes
Electrolytes are not automatic. Long or heavy sweating and vomiting or diarrhea need different approaches; food, losses and medical restrictions matter. Ask a clinician or pharmacist when illness is involved.
If you have kidney disease, heart disease, high blood pressure, sodium restrictions, or take blood-pressure or diuretic medication, do not add potassium supplements or extra sodium without asking your clinician.
Frequently asked
How much water should I drink on keto?
WaterDailyGoal uses 33 ml/kg for a beverage planning estimate. The 30–40 ml/kg scenarios and activity/climate coefficients are site assumptions, not validated personal requirements or NAM/EFSA formulas.
Why does keto make you lose water?
Carbohydrate is stored as glycogen, and glycogen holds water. When carbs drop, glycogen and the water bound to it fall too, especially during the first low-carb weeks.
Do I need electrolytes on keto?
Electrolytes are not automatic. Long or heavy sweating and vomiting or diarrhea need different approaches; food, losses and medical restrictions matter. Ask a clinician or pharmacist when illness is involved.
Sources
- 1.U.S. National Academies (IOM/NAM), 2005 — Adequate total water intake of about 3.7 L/day for men and 2.7 L/day for women, including water from food and all beverages.Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate, Summary: water adequate intakes; drinks and food
- 2.Mayo Clinic — General guidance of roughly 2.7–3.7 L of total fluids a day, with thirst and pale-yellow urine as everyday checks.