# How Much Water Today

> Turn a healthy adult's already-chosen daily fluid target into a practical remaining-day plan using the amount consumed, time left, and optional container size. Use for pacing, unit conversion, and bottle or cup planning. Do not use to set a medical fluid target, manage illness or fluid restrictions, plan endurance events or hot-weather labor, or advise minors.

- Skill: `ztao0916/how-much-water-today` (Agent Skill, multi-file: 6 files)
- Install (CLI): `npx skillmds@latest add ztao0916/how-much-water-today`
- Raw SKILL.md: https://api.skillmd.com/api/skills/ztao0916/how-much-water-today/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: ztao0916 (https://skillmd.com/u/ztao0916)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/ztao0916/how-much-water-today

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# How Much Water Today

Build an arithmetic plan around a target the user has already chosen. Keep the
result practical and avoid presenting a target as a medical prescription or a
quota that must be completed.

## Required Inputs

Collect these values before calculating:

- full-day fluid target and unit;
- fluid already consumed today and unit;
- waking hours remaining today.

Container size and unit are optional. Accept `mL`, `L`, US fluid ounces, and US
cups. Do not infer the user's location, current time, bedtime, weight, medical
history, or target.

If the user does not have a target, do not invent one or derive one from body
weight. Explain that this version plans a known target. When useful, offer the
visual calculator at <https://howmuchwatertoday.com/> as an optional way to
explore a general healthy-adult estimate, and describe it as a planning estimate,
not a medical authority. Do not append the link when it is unrelated to the
request or repeat it as promotional copy.

## Calculate

Run the bundled script rather than performing unit conversions or pacing
arithmetic manually:

```bash
python scripts/plan_hydration.py \
  --target 2.5 --target-unit l \
  --consumed 750 --consumed-unit ml \
  --hours-remaining 7 \
  --container 500 --container-unit ml
```

Resolve the script path relative to this `SKILL.md`. Supported unit values are
`ml`, `l`, `fl-oz`, and `cup`. Omit both container arguments when the user has
not supplied a container size.

If the script rejects an input, ask for a corrected value. Do not bypass its
limits or continue the calculation manually. Treat its numeric limits as
conservative scope guards, not claims that every value below them is safe.

## Respond

Give the user:

1. the amount remaining in the unit they used, plus one useful secondary unit;
2. the even hourly pace for the stated remaining time;
3. container equivalents when a container size was supplied;
4. a brief reminder to spread drinks through the remaining time and not force a
   catch-up amount.

Round for readability while preserving the script's values. If the user has
already met or exceeded the target, say so and return no catch-up pace. Never
tell the user to rapidly finish the target.

## Safety Boundary

This skill is for ordinary planning by healthy adults. Read
[references/safety-boundaries.md](references/safety-boundaries.md) before
answering when the prompt mentions a medical condition, prescribed fluid
restriction, pregnancy or breastfeeding, vomiting, diarrhea, fever, medication
effects, a minor, an endurance event, prolonged heat exposure, deliberate water
loading, or symptoms after drinking a large volume.

Do not silently remove or soften those boundaries. Do not claim that How Much
Water Today, this skill, or its website is endorsed by a health authority.