Electrolyte Supplement Calculator (Hydration)

Electrolyte Supplement Calculator (Hydration)

Calculate daily electrolyte supplement needs for sodium, potassium, and magnesium based on sweat rate, workout intensity, heat, keto diets, and water loss.

Lbl select preset
Parameters & Inputs
Lbl baseline fluid mini 2.5 Unit l
Unit kg
90 Unit min (1.5 Unit hours)
1.2 Unit liters per hour
920 Unit mg per l
Lbl heat multiplier 1.15Unit times
Lbl temp short26 Unit deg c
Lbl humidity short55%
Lbl high order factors
Lbl acclimatization
Lbl altitude
Lbl caffeine
Lbl deducted from gap
Lbl food sodium mini
Lbl food potassium mini
Lbl food magnesium mini
Lbl sodiumUnit mg
3,604
Lbl sweat loss short 1,904 Unit mg
Lbl potassiumUnit mg
3,014
Lbl sweat loss short 414 Unit mg
Lbl magnesiumUnit mg
352
Lbl sweat loss short 52 Unit mg
Lbl total fluid shortUnit l
4.5
153 Unit fl oz
100210-260450+
Lbl target osmolality240 mOsm/L

Lbl optimal tonicity

Desc drinking dilution 2.07 Unit l Desc drinking water paced

Lbl cation breakdown titleLbl chart sync
Lbl sodium3,604 mg net / 4,204 mg gross
Lbl potassium3,014 mg net / 3,814 mg gross
Lbl magnesium352 mg net / 452 mg gross
Legend food creditLegend net deficit
Lbl interactive converter1000 mg Na+ = 2,542 mg Salt
Desc salt compound ratio~ 1/2 tsp

Disclaimer title Disclaimer health

Primary Metric3,604 mg
Efficiency / Capacity4.5 L
Net Output240 mOsm/L

Client-Side Processing

High-performance calculation executed entirely in browser memory.

Zero Server Upload Privacy

All payloads remain strictly local with zero external server communication.

Production Ready Export

Clean, optimized output formats ready for immediate deployment.

ToolsAA•100% Client-Side Private Web Utilities
Technical Reference & Architecture Guide

Electrolyte Supplement Calculator (Hydration) Guide

Calculate daily electrolyte supplement needs for sodium, potassium, and magnesium based on sweat rate, workout intensity, heat, keto diets, and water loss.

Electrolyte Supplement Calculator (Hydration) Guide — Client-Side In-Memory Architecture & Data Flow
Electrolyte Supplement Calculator (Hydration) Guide — Client-Side In-Memory Architecture & Data Flow

Key Parameters & Controls

Sweat Sodium ConcentrationMilligrams per Liter (mg/L)

Individual physiological sodium density in eccrine perspiration, clinically ranging from 400 mg/L in heat-acclimated athletes to over 1,800 mg/L in genetic salty sweaters.

Default: 920 mg/L (Clinical Median)
Hourly Sweat RateLiters per Hour (L/h)

Gross perspiration loss rate per 60 minutes of exertion, governed by metabolic wattage, air speed convection, body mass, and thermal environment.

Default: 1.1 L/h
Dietary Metabolic Natriuresis StateNutritional Physiology Regime

Metabolic regime modifying renal sodium clearance. Carbohydrate restriction plummets serum insulin, suppressing renal epithelial sodium channels (ENaC) and increasing daily sodium excretion by 1,500 to 2,500 mg.

Default: Standard Balanced (2,300 mg Base Na+)
Solution Tonicity & OsmolalityMilliosmoles per Kilogram (mOsm/kg)

Osmotic pressure of the ingested fluid relative to human blood plasma (285-295 mOsm/kg). Solutions between 200-260 mOsm/kg (hypotonic) maximize gastric emptying and intestinal water absorption.

Default: 230 mOsm/kg (Optimal Hypotonic)
Elemental vs Compound Mineral YieldStoichiometric Mass Fraction (%)

The exact proportion of active mineral ion within a chemical salt carrier: Sodium Chloride is 39.34% elemental Na+, Potassium Chloride is 52.44% elemental K+, and Magnesium Bisglycinate is approximately 14.1% elemental Mg2+.

Default: Exact Stoichiometric Ratios

Pro Tips & Best Practices

The Elemental vs Chemical Salt Mass Trap

Never confuse chemical salt weight with active elemental mineral content. Pure table salt (NaCl) is only 39.3% sodium by weight; consuming 1,000 mg of table salt provides merely 393 mg of elemental sodium. Similarly, Magnesium Bisglycinate powder contains only ~14% elemental magnesium, meaning 1,500 mg of compound provides only 210 mg of active magnesium. Formulate exclusively by elemental targets to prevent massive under-dosing.

Exercise-Associated Hyponatremia (EAH) and Plain Water Overload

Drinking excessive plain water or low-electrolyte beverages during prolonged endurance events (>3 hours) dilutes extracellular serum sodium below 135 mmol/L. This osmotic gradient forces water into brain cells, triggering headache, confusion, pulmonary edema, and potentially fatal cerebral swelling. Never rehydrate with plain water when sweat losses exceed 2% of body mass without matching sodium replenishment.

The 1,000 mg Osmotic GI Dumping Threshold

Ingesting more than 800-1,000 mg of sodium or 250 mg of elemental magnesium in a single concentrated bolus creates a hypertonic environment in the intestinal lumen. The body rushes water from vascular circulation into the gut via osmosis to dilute the solute, provoking acute abdominal cramping and explosive osmotic diarrhea within 20 to 45 minutes. Always disperse your dose across 500-750 ml of water and sip progressively.

The Keto Natriuretic Surge and Potassium Safety Guardrail

When entering nutritional ketosis or water fasting, circulating insulin collapses, signaling the kidneys to rapidly dump sodium into urine. This requires 4,000 to 5,000 mg of total sodium daily to prevent orthostatic dizziness and fatigue. However, never attempt to mega-dose potassium salts in dry powder or concentrated shots; oral potassium boluses exceeding 20 mEq (780 mg elemental K+) without water can cause acute gastric mucosal irritation and cardiac conduction disturbances.

Common Gotchas & Troubleshooting

⚠️Sudden watery diarrhea or severe stomach gurgling 30 minutes after drinking an electrolyte mix

Your solution is hypertonic (>300 mOsm/kg) or contains fast-transit magnesium compounds (such as magnesium oxide or high-dose citrate). Dilute the powder with an additional 250-400 ml of plain water, switch to highly bioavailable Magnesium Bisglycinate or Malate, and cap elemental magnesium intake at 150 mg per serving.

⚠️Severe calf cramps, quad twitches, or toe spasms waking you up during the night after a hard workout

Night cramping is rarely simple dehydration; it stems from acute neuromuscular hyperexcitability caused by unreplaced sodium deficit combined with low extracellular magnesium. Increase total post-workout sodium replacement to at least 125% of estimated sweat loss, and ingest 200 mg of elemental magnesium glycinate with a carbohydrate-containing recovery meal.

⚠️Orthostatic lightheadedness (dizziness when standing up), brain fog, and headache on a low-carb or keto diet

This is textbook 'keto flu' caused by acute hypovolemia secondary to renal sodium excretion. Dissolve 1/2 teaspoon of standard table salt (~1,150 mg elemental sodium) into 300 ml of warm bone broth or lemon water and sip immediately; arterial blood volume will normalize within 20 minutes.

⚠️Puffy fingers, swollen ankles, and tight ring fit during long hot summer hikes despite taking salt pills

This indicates peripheral dependent edema from vasodilation and excessive, unpaced sodium loading exceeding fluid intake. Discontinue salt capsules temporarily, maintain steady plain water sips to allow renal atrial natriuretic peptide (ANP) to normalize hydrostatic fluid balance, and keep arms moving above heart level.

Frequently Asked Questions

How to calculate electrolyte replacement during exercise?▼

Electrolyte replacement equals Sweat Rate (L/hr) multiplied by Exercise Duration (hr) multiplied by Sweat Sodium Concentration (typically 900 mg/L). For example, a runner sweating 1.2 L/hr for 2 hours loses 2.4 liters of fluid and approximately 2,160 mg of elemental sodium. Sports science guidelines recommend replacing 50% to 80% of lost sodium during the workout (roughly 500-800 mg Na+ per hour) along with 100-200 mg potassium, leaving the remainder to be replenished via post-workout nutrition.

How much sodium potassium and magnesium do I need on keto?▼

Clinical consensus for ketogenic diets recommends 4,000 to 5,000 mg of elemental sodium (equivalent to 10-12 grams of table salt), 3,000 to 3,800 mg of potassium, and 300 to 500 mg of bioavailable elemental magnesium per day. These targets are significantly higher than standard dietary guidelines because carbohydrate restriction lowers circulating insulin, which suppresses aldosterone and causes the renal tubules to excrete sodium and water at accelerated rates.

What is the difference between table salt and elemental sodium?▼

Table salt is chemical Sodium Chloride (NaCl), which contains 39.34% elemental sodium and 60.66% chloride by atomic weight. Therefore, 1 gram (1,000 mg) of table salt provides only 393 mg of elemental sodium. To obtain 1,000 mg of true elemental sodium, you must consume approximately 2.54 grams (or about 1/2 level measuring teaspoon) of pure table salt.

Why do commercial electrolyte drinks cause stomach cramps or nausea?▼

Disclaimer: This tool is provided strictly for educational and informational purposes only and does not constitute formal financial advice or a binding loan commitment. Please consult a qualified financial advisor before making decisions. Stomach distress occurs when an electrolyte drink has an osmolality exceeding human blood plasma (>295 mOsm/kg), usually caused by mixing too much powder into too little water or combining high sugar concentrations with heavy mineral loads. This hypertonic fluid halts normal gastric emptying and pulls water out of bloodstream capillaries into the gut lumen. Restoring drink concentration to a hypotonic range (200-260 mOsm/kg) by adding water resolves the cramping immediately.

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