How much water should you bring hiking?
Too little and you bonk, too much and you haul dead weight. Enter your time on trail, the effort, and the heat, and get a number you can actually pack.
Carry about
about 70 fl oz, or 2 one-liter bottles
2 L
per person
0.5 L/hr
for these conditions
Sip steadily rather than gulping at breaks, and top off at any reliable water source.
Water per person by time and temperature
A quick reference for a moderate-effort hike. Scale up for hard climbs and down for an easy stroll.
| Time | Cool | Mild | Warm | Hot |
|---|---|---|---|---|
| 2 hours | 0.75 L | 1 L | 1.25 L | 1.5 L |
| 4 hours | 1.75 L | 2 L | 2.5 L | 3 L |
| 6 hours | 2.5 L | 3 L | 3.75 L | 4.5 L |
| 8 hours | 3.5 L | 4 L | 5 L | 6 L |
Water weighs about 1 kg per liter, so on long days a filter and a refill plan beat carrying it all. See how we research and rate.
The reservoir to carry it in
Once you know your water target, the HydraPak Contour is our best-overall bladder: a low-profile 3L reservoir with a high-flow bite valve, sized so a full day of water rides flat against your back. See all hydration picks →

HYDRAPAK
HydraPak Contour Hydration Reservoir (1.5L, 2L, or 3L)
- Capacity
- 1.5L / 2L / 3L
- Weight (3L)
- 5.4 oz (155 g)
- Closure
- Zip Slide-Seal, fully reversible
- Bite valve
- Comet self-sealing, thumb shutoff
- Dishwasher safe
- Yes (top rack)
- Hose connection
- Quick-disconnect, magnetic clip
The Contour's 3D-welded shell and internal Shape-Loc baffles keep it flat and slim so it slides into a loaded pack without fighting the sleeve. Its fully reversible body and dishwasher-compatible materials make it the easiest bladder on the market to clean and dry completely.
Researched, not personally tested: picks come from specs, verified-owner reviews, and expert sources, scored into the Kit Score. As an Amazon Associate I earn from qualifying purchases. We may earn a commission from links here, at no extra cost to you. How we research →
Frequently asked questions
How much water should you drink per hour while hiking?
Plan on about half a liter (17 fl oz) per hour of moderate hiking in mild weather. Drop to roughly 0.4 liters per hour for easy walking in cool air, and climb to 0.75 liters or more per hour for hard efforts or hot days.
How much water do you need for a 10 mile hike?
A 10 mile hike takes most people 4 to 6 hours, so plan about 2 to 3 liters in mild conditions, and 4 liters or more if it is hot or strenuous. Carry less and filter at a reliable source when you can, since water is heavy.
How much does water weigh?
Water weighs about 1 kilogram per liter, or 2.2 pounds. A full 3 liter reservoir adds roughly 6.6 pounds to your pack, which is why planning refills beats carrying a whole day of water at once.
Should I bring electrolytes or just water?
For hikes under about 2 hours, plain water is fine. On longer or hotter days when you are sweating heavily, add an electrolyte mix so you replace sodium too, not just fluid.
How can I carry less water?
Map water sources before you go and carry a filter or purifier. Then you only carry enough to reach the next reliable source, which can cut several pounds on a long day.
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