Electrolyte Calculator

Estimate electrolyte needs from weight, activity and sweat — see sodium, potassium, magnesium needs and hydration.

Electrolyte Calculator

Estimate electrolyte needs from weight, activity and sweat — see sodium, potassium, magnesium needs and hydration.

Weight (kg)

Activity hours/day

Sweat level

Enter values above and click Calculate — results will appear here with the formula explained.

Sodium 500mg per hour moderate, 300 low, 800 high; Potassium 200mg per hour; Magnesium 50mg per hour

How does this work?

Electrolyte needs scale with sweat. Sodium 500mg per hour moderate, potassium 200mg, magnesium 50mg. Low and high adjust 40%.

This is for exercise, not resting. Daily needs are lower: sodium 1500-2300mg, potassium 2600-3400mg, magnesium 310-420mg.

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Disclaimer: Results are estimates for informational purposes only and do not constitute professional medical advice.

Quick Answer

Electrolyte Calculator: Estimate electrolyte needs from weight, activity and sweat — see sodium, potassium, magnesium needs and hydration. Formula: Sodium 500mg per hour moderate, 300 low, 800 high. Example: With 70kg, 1 hour moderate: sodium 500mg, potassium 200mg, magnesium 50mg extra.

How to Use This Calculator

1Enter weight, activity hours per day and sweat level.
2Calculate to see sodium, potassium, magnesium needs for exercise.
3Replenish with sports drink or salt + banana.

Formula Used

Sodium 500mg per hour moderate, 300 low, 800 high; Potassium 200mg per hour; Magnesium 50mg per hour

Electrolyte needs scale with sweat. Sodium 500mg per hour moderate, potassium 200mg, magnesium 50mg. Low and high adjust 40%.

This is for exercise, not resting. Daily needs are lower: sodium 1500-2300mg, potassium 2600-3400mg, magnesium 310-420mg.

AdSense ready — add NEXT_PUBLIC_GOOGLE_ADSENSE_PUBLISHER_ID

728×90 — AdSense

Worked Example

With 70kg, 1 hour moderate: sodium 500mg, potassium 200mg, magnesium 50mg extra.

AdSense ready — add NEXT_PUBLIC_GOOGLE_ADSENSE_PUBLISHER_ID

728×90 — AdSense

Related Calculators

Hydration Calculator

Estimate daily water needs from weight, activity and climate — see liters, cups and hourly intake.

Sodium Intake Calculator

Check sodium intake from foods and salt — see daily total, % of limit, and low-sodium swaps.

Water Intake Calculator

Estimate daily hydration needs from body weight and activity level.

Sodium Intake Calculator

Check sodium intake from foods and salt — see daily total, % of limit, and low-sodium swaps.

Frequently Asked Questions

QDo I need supplements?

For <1 hour, water is enough. Over 1 hour or high sweat, electrolytes help.

QHow much sodium daily?

1500-2300mg. Athletes may need 3000+ with heavy sweat.

QMagnesium?

310-420mg daily. Nuts, seeds and greens are sources.

Formula Used

Sodium 500mg per hour moderate, 300 low, 800 high; Potassium 200mg per hour; Magnesium 50mg per hour

Electrolyte needs scale with sweat. Sodium 500mg per hour moderate, potassium 200mg, magnesium 50mg. Low and high adjust 40%.

This is for exercise, not resting. Daily needs are lower: sodium 1500-2300mg, potassium 2600-3400mg, magnesium 310-420mg.