Daily Water Requirement Calculator

Daily Water Requirement Calculator for Nutrition. The number is a planning estimate associated with the chosen factor, not a command to drink that amount. Ongoing losses, balance, examination and the clinical trajectory still determine management.

For shared guidance on choosing a tool and documenting results, read the clinical calculator workflow.

How this calculator works

Daily volume is assessment weight multiplied by an independently selected fluid factor. NICE CG32 describes adult nutrition-support planning; its context is not pediatric maintenance or emergency fluid resuscitation.

When to use this calculator

Check the multiplication in an adult nutrition-support plan. Document why the factor and weight were chosen, then reconcile fluid from food, drinks, feeds and intravenous sources against the complete plan.

Inputs used

  • Adult assessment weight in kg
  • Clinician-selected fluid factor in mL/kg/day

Clinical interpretation

The number is a planning estimate associated with the chosen factor, not a command to drink that amount. Ongoing losses, balance, examination and the clinical trajectory still determine management.

Worked example

For 70 kg and an entered 30 mL/kg/day, the result is 2100 mL/day. If a plan already supplies 1500 mL from feeds and 500 mL from other sources, only 100 mL separates that total from this arithmetic estimate; do not add another 2100 mL automatically.

Limitations and safety notes

The former pediatric-style algorithm and automatic fever multiplier are removed. Cardiac or kidney disease, critical illness, electrolyte disturbance and fluid restriction need individualized decisions beyond this calculation.

Frequently asked questions

Is every possible input factor a recommended dose?

No. Input limits are technical bounds. The factor must come from an appropriate clinical assessment, not from the fact that the field accepts it.

References

  • https://www.nice.org.uk/guidance/cg32/chapter/Recommendations

Editorial review and citation methodology

Maintained by the Quick Medical Calculator Editorial Team. Content record date: September 9, 2026. A content date is not evidence of independent clinical review. Individual clinical sign-off is not recorded on this page.

  • Prefer original validation studies for scoring systems and prediction tools.
  • Use current specialty society guidance, transplant allocation policy, public health guidance, or regulator resources when they govern clinical use.
  • Include limitations and safety notes when a calculator is population-specific, context-dependent, or unsuitable as a standalone decision tool.

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