Hiking Water Needs Calculator
Fill in the values and the answer updates as you type.
How the Hiking Water Needs Calculator works
Base drinking rates are 0.4 L per hour for easy walking, 0.6 L for moderate effort, and 0.8 L for strenuous effort. Above 20 °C the rate rises by 4 percent for every degree. Water to carry = hours between refills × drinking rate. Water weighs 1 kg per liter, so carrying extra has a real cost. Carry more in dry terrain, at altitude, or when the next source is uncertain. Example: with Time between water sources 5 h, Air temperature 25 °C, and Effort level Moderate, the result is Water to carry (liters) = 3.6; Bottles to fill = 4; Drinking rate (liters per hour) = 0.72.
Inputs and results
The Hiking Water Needs Calculator takes 4 inputs and gives 4 results.
What you enter
- Time between water sources (h) — starts at 5.
- Air temperature (°C) — starts at 25.
- Effort level — starts at Moderate. Choose from: Easy, Moderate and Strenuous.
- Bottle size (L) — starts at 1.
What you get
- Water to carry (liters)
- Bottles to fill
- Drinking rate (liters per hour)
- Water to carry (US fl oz)
Example: Hiking Water Needs Calculator with the starting values
With time between water sources 5 h, air temperature 25 °C, effort level Moderate and bottle size 1 L, the calculator returns:
| Water to carry (liters) | 3.6 |
|---|---|
| Bottles to fill | 4 |
| Drinking rate (liters per hour) | 0.72 |
| Water to carry (US fl oz) | 122 |
Change any value above and the results update straight away.
Hiking Water Needs Calculator FAQ
How do I use the Hiking Water Needs Calculator?
Enter time between water sources, air temperature, effort level and bottle size in the fields, then read water to carry (liters), bottles to fill, drinking rate (liters per hour) and water to carry (us fl oz) in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Hiking Water Needs Calculator calculate?
How much water to carry for a hike, by time, heat, and effort. It returns water to carry (liters), bottles to fill, drinking rate (liters per hour) and water to carry (us fl oz) from the 4 values you provide.
What values does the Hiking Water Needs Calculator start with?
It opens with time between water sources 5 h, air temperature 25 °C, effort level Moderate and bottle size 1 L so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Hiking Water Needs Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Hiking Water Needs Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.