Hydration by Activity
Add fluid needs from exercise.
About Hydration by Activity
Hydration needs for Hydration by Activity start from body weight and add allowances for prolonged activity and hot conditions, where sweat losses climb. Fluid needs track body size and sweat loss, so a fixed daily target fits nobody precisely.
Formula
Hydration by Activity
Water = 33 mL x weight + activity allowance + heat allowance
- base
- About 33 mL per kilogram of body weight
Worked example
With the default values below, Hydration by Activity returns Daily Water of 2.31. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Body weightminimum 0 kg
- 70 kg
- Activityminimum 0 min
- 45 min
- Temperatureminimum 0 C
- 25 C
Results
- Daily Water
- 2.31 L
- Base Water
- 2.31 L
- Activity Extra
- 0.00 L
Step by step
- 1Values used
- 2Hydration by Activity
- 3Daily Water= 2.31 L
- 4Base Water= 2.31 L
- 5Activity Extra= 0.00 L
Assumptions and limits
- The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
- These figures are population-average estimates for general planning only and are not medical or dietetic advice. Individual energy and nutrient needs vary widely with body composition, activity, medication and health status. Consult a qualified health professional or registered dietitian before making significant changes to what you eat, and especially if you are pregnant or breastfeeding, are under 18, or have a medical condition or a history of disordered eating.
- This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
These figures are population-average estimates for general planning only and are not medical or dietetic advice. Individual energy and nutrient needs vary widely with body composition, activity, medication and health status. Consult a qualified health professional or registered dietitian before making significant changes to what you eat, and especially if you are pregnant or breastfeeding, are under 18, or have a medical condition or a history of disordered eating.
Frequently Asked Questions
How is Hydration by Activity calculated?
Water = 33 mL x weight + activity allowance + heat allowance Hydration needs for Hydration by Activity start from body weight and add allowances for prolonged activity and hot conditions, where sweat losses climb.
Why does Hydration by Activity matter?
Fluid needs track body size and sweat loss, so a fixed daily target fits nobody precisely.
What values do I need to enter?
This calculator takes 3 inputs: Body weight, Activity, Temperature. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.