How much water should you drink a day?

Wondering how much water you need to drink each day? Your ideal daily water intake depends on your weight, activity level, and climate—and it’s not always as simple as the 8 glasses a day rule. Use our Hydration Calculator to find out exactly how many litres of water you should drink a day and how many refills of an ION8 bottle will keep you on track.

Your Data, Your Privacy – We don’t store or record any of the information you enter. This is just for you to check your hydration levels—nothing more.

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Daily liquid intake

Daily Water Intake (250ml/glass)
Zero Water
Daily Coffee/Tea/Soft Drinks Intake (125ml/glass)
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Daily Alcohol/Wine/Beer Intake (125ml/glass)
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Daily Electrolyte Drink/Milk Intake (250ml/glass)
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Results

Your daily hydration target
Total hydration target
(-) Estimated water from foods
Hydration target from fluids:
How much you currently drink
Water Intake
Coffee/Tea/Soft Drinks Intake (-15%)
Alcohol/Wine/Beer Intake (-40%)
Electrolyte Drink/Milk Intake (+20%)
Total daily fluid intake:
Your daily hydration gap
Hydration target from fluids
(-) Total daily fluid intake
Total gap:
Bottle sizes and refill counts for your daily hydration
Pod
320-400ml
Refills
Shop Pod
Slim
500-600ml
Refills
Shop Slim
Tour
750ml
Refills
Shop Tour
Quench
920-1200ml
Refills
Shop Quench
Shop All Bottles Hydration Information

How Much Water Should You Drink Per Day?

The amount of water you should drink daily isn't one-size-fits-all. Factors like your age, weight, gender, and exercise habits all affect how much water your body needs. While the standard guideline suggests around 2 litres of water per day, many people need more—especially if you're active or live in warmer climates.

Use our calculator to get a personalised hydration goal based on your unique lifestyle and learn how many litres of water a day will keep you hydrated.

Why Is Staying Hydrated So Important?

Proper hydration helps your body perform at its best by:

✔ Boosting energy levels and concentration
✔ Supporting digestion and metabolism
✔ Improving physical performance
✔ Regulating body temperature
✔ Preventing headaches and fatigue

Not drinking enough water every day can leave you feeling sluggish, dehydrated, and more prone to illness. For more advice on the benefits of hydration, explore our Hydration Advice Centre.

How to Calculate How Much Water You Need a Day

Our Hydration Calculator makes it simple to calculate your daily water intake. Just enter your:

  • Height
  • Weight
  • Climate
  • Activity level
  • Current daily water intake

We'll instantly calculate how much water you should drink each day and convert your result into how many refills of an ION8 bottle you'll need—whether that's our 350ml 500ml, 750ml, or 1-litre bottles.

How Many Litres of Water Should You Drink Per Day?

The recommended daily water intake varies depending on your body size and activity level. As a general rule:

Weight : Water Intake (Litres per Day)

  • 50-60kg : 1.5-2L
  • 70-80kg : 2-2.5L
  • 90kg+: 2.5-3L

Want a personalised result? Use our Hydration Calculator to find out exactly how much water you should drink each day based on your body and lifestyle.

How Much Water Should You Drink for Weight Loss?

Drinking the right amount of water can support weight loss by:

  • Boosting metabolism
  • Suppressing appetite
  • Improving digestion
  • Replacing high-calorie drinks

Use our calculator to find your personalised daily water intake and read more at our Hydration Centre.

How to Stay Hydrated Every Day

Hitting your hydration goals is easier with the right tools:

  • Carry an ION8 reusable water bottle
  • Set hourly hydration reminders
  • Add ice or fruit to your water for a refreshing boost
  • Track your refills throughout the day

Learn More in Our Hydration Advice Centre

Looking for expert tips on hydration? Visit the ION8 Hydration Advice Centre for articles like:

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