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Water Intake Calculator

Most "8 cups a day" advice is a myth. Real fluid need scales with bodyweight, training, and climate. We use the IOM Dietary Reference Intakes.

Inputs

Result

  • Daily water3.1L
  • Roughly13× 250ml cups

Calculations run locally in your browser. Nothing is sent to a server.

How it works

Base: 35 ml/kg (IOM DRI). +500 ml for moderate activity, +1000 ml for heavy. +500 ml for hot/humid. Includes ~20% from food.

References

FAQ
Does coffee count?

Yes. Caffeine is a mild diuretic in non-habituated users, but the fluid load still nets positive.

Can I drink too much?

Yes, hyponatremia from over-drinking + sodium loss happens in endurance athletes. Stay below ~1.5 L/hr.

Why does Ascend track water?

Hydration moves performance ±10%. Each glass logged = AP (achievement points) toward your streak.

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