Water Intake Calculator
Convert the NHS general 6–8 cups/glasses hydration guide into counts of your cup or bottle.
How to use
- Enter your cup or bottle volume in millilitres.
- Select pregnancy/breastfeeding, hot environment, prolonged activity, or illness/recovery when applicable, then calculate.
Capabilities and scope
The current implementation is not a weight-based formula; it shows a general 1.5–2 L reference, container count, and circumstances that may require more fluid.
How it works
It divides 1.5 L and 2 L by the entered container size; circumstance checks do not calculate an exact extra amount.
Example
With a 500 ml bottle, 1.5–2 L is about 3–4 bottles.
Interpretation
Circumstance checkboxes do not add a fixed number of millilitres.
Useful for
- Translate a general hydration guide into a familiar bottle count
- Flag situations where fluid needs may be higher than the general guide
Before you use it
- It is not an individualized fluid prescription; clinical fluid restrictions for conditions such as heart or kidney disease take priority.
Edge cases
- Container volume must be greater than zero.
Standards and references
Frequently asked questions
Why is there no body-weight input?
The current runner intentionally uses a general NHS hydration guide rather than a fixed ml-per-kg formula.