Updated: 2026-11-09 · Version 1.0
How much water per person in an emergency?
Quick answer: Ready.gov and the CDC use 1 gallon (≈3.8 L) per person per day, for at least three days (the CDC suggests two weeks if possible). Brazil's Civil Defense cites 2 L/day and Finland at least 5 L. Add more for heat, children, pregnancy and pets.
Comparison
| Source | Per person/day | Family of 4 · 3 days |
|---|
| US (Ready.gov / CDC) | 1 gal ≈ 3.8 L | 12 gal ≈ 45 L |
| Brazil (Civil Defense, via press) | 2 L | 24 L |
| Finland (official) | ≥ 5 L | ≥ 60 L |
Use the kit calculator to adjust.
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FAQ
Is 1 gallon per day enough?
It is the minimum reference used by US agencies; adjust for climate and needs.
How long can stored water last?
It depends on the container and storage. Review every 6 months.
Sources
- Ready.gov — Build a Kit (2026-07-01) · Tier 1 (official)
- CDC (2025-06-27) · Tier 1 (official)
- 72tuntia.fi (Finland) · Tier 1 (official)
- Brazil MIDR note 2026-11-07; 2 L/day via press · Tier 1/3
More guides
Educational content; does not replace official guidance.