Electrolyte Balance Calculator
Estimate your daily electrolyte needs for sodium, potassium, magnesium, and calcium based on body weight, activity level, and sweat rate.
Electrolytes are minerals in your blood and bodily fluids that carry an electric charge. They are essential for muscle contractions, nerve signals, hydration, and pH balance. When you sweat, you lose electrolytes — not just water — and replenishing them is critical for health and performance.
The Four Key Electrolytes
Sodium (Na⁺) The primary electrolyte in blood plasma. Regulates fluid balance and blood pressure. Reference range: 135–145 mEq/L in blood. Daily need: 1,500–2,300 mg. Athletes and heavy sweaters may need 3,000–5,000 mg on training days.
Potassium (K⁺) The primary electrolyte inside cells. Critical for heart rhythm, muscle function, and blood pressure regulation. Daily need: 2,600–3,400 mg (women) / 3,000–3,400 mg (men). Found in bananas, sweet potatoes, avocados, and spinach.
Magnesium (Mg²⁺) Involved in over 300 enzymatic reactions. Essential for muscle relaxation, sleep, energy production, and bone health. Daily need: 310–420 mg. Magnesium is frequently deficient in modern diets.
Calcium (Ca²⁺) Essential for bone density, muscle contraction, and nerve transmission. Daily need: 1,000–1,200 mg. Found in dairy, leafy greens, and fortified foods.
Sweat and Electrolyte Loss
A typical person loses approximately 0.5–1.5 liters of sweat per hour of moderate exercise, with a sodium concentration of 200–1,000 mg per liter. Athletes training in heat can lose far more.
This calculator estimates your daily electrolyte targets based on your weight, activity level, and sweat intensity. Results are general guidelines — clinical conditions (kidney disease, heart failure, etc.) change these recommendations significantly. Consult a doctor for medical guidance.
Metric and Imperial Support
Enter weight in kilograms (kg) or pounds (lbs). 1 kg = 2.205 lbs.