Electrolyte Drink Mix Calculator
Turn your bottle and sweat into a simple mix plan
Electrolyte mixes, sweat and common questions
Why does sodium in a drink matter when I sweat?
When you sweat you lose fluid and electrolytes, especially sodium. Plain water replaces fluid but not sodium, which matters more during long or very sweaty sessions. A drink with some sodium can help you hold on to fluid better and replace a small part of what is lost in sweat.
Is this calculator giving me medical rehydration doses?
No. Clinical oral rehydration solutions for illness and dehydration use different recipes and are designed for diarrhoea, vomiting or medical care. This page is only for everyday training and events in otherwise healthy adults, using typical sports-drink style ranges.
Where do the sodium targets come from?
Many sports and hydration guidelines describe sodium bands for drinks used with longer or hotter exercise. They usually suggest that an “in-exercise” drink contains some sodium per litre, rather than being completely plain water, especially for heavy or salty sweaters. The ranges here are a simplified version for planning.
Does more sodium always mean better performance?
Not necessarily. Too little sodium over long, sweaty sessions can be a problem, but too much can be an issue as well, especially if you have high blood pressure, kidney disease or heart conditions. That is why this calculator sticks to ballpark ranges and reminds you to follow medical advice.
What if I do short, light sessions?
Many people doing short, light or cool-weather sessions are fine with water and everyday food. In that case, you might not need a specific electrolyte drink for performance at all. The tool is more useful for longer, sweatier efforts.
Can I use this for kids, pregnancy or illness?
No. Children, pregnant people and anyone who is ill or frail need separate clinical guidance on fluids and electrolytes. This page is not designed for those situations and should not be used to make treatment decisions.
Should I match the exact number the tool gives?
Think of this as a starting point, not a target you must hit exactly. Taste, stomach comfort, climate, pace and coach or clinician rules all matter too. It is fine to adjust the mix up or down as you test what works for you.
How to use this electrolyte drink mix calculator
This tool is built to turn scattered label numbers into one simple bottle plan. You tell it your body weight, how big your bottle is, how sweaty you feel and how much sodium is in your mix. It then suggests a sodium target per litre and per bottle, plus scoops per bottle that roughly hit that target.
1. Choose units and enter your body weight
Start by picking whether you prefer US units (lb and fl oz) or metric (kg and mL). US mode works in pounds and fluid ounces; metric mode uses kilograms and millilitres and updates the labels automatically. Add your current body weight so the tool can gently scale the sodium target.
2. Add your typical bottle size
Next, enter the size of one bottle you normally drink during training. Common examples are 16–24 fl oz or roughly 500–750 mL. The calculator converts this into litres behind the scenes so it can show both mg per bottle and mg per litre cleanly.
3. Pick your sweat / saltiness level
Use the sweat dropdown to pick whether you feel like a lighter, medium or salty/heavy sweater during tough sessions. People who finish with salt marks on clothes or skin, or who drip a lot, usually sit closer to the salty/heavy end than the lighter one.
4. Enter sodium per scoop from your label
Look at your drink mix or tablet label and find the sodium per scoop or serving in milligrams. Type that number into the sodium box. The calculator uses it to work out how many scoops per bottle land close to the target sodium range for your weight and sweat level.
5. Read the suggested mix per bottle
When you tap Plan electrolyte mix per bottle, the tool shows:
- Your weight and bottle size in your chosen units.
- A target sodium concentration (mg per litre).
- Target sodium per bottle in milligrams.
- Suggested scoops per bottle using your mix.
- The actual sodium you would get with that scoop count.
The aim is to give you a clear, readable plan for one bottle, not to nail a perfect lab formula.
6. Use the note and summary for planning
The note box lets you tag the scenario, such as “long run in heat”, “indoor intervals” or “race-day plan”. That note appears in the copyable summary so you can paste it into your training log, spreadsheet or a message to a coach or clinician.
Treat this as a starting point you can test. Real comfort depends on gut tolerance, total fluid intake, pace, food, altitude and more. Any medical conditions or specialist instructions should overrule the simple mix plan shown here.
How the electrolyte drink mix math works
The math is intentionally simple so you can sanity-check it with a basic calculator if you want. It combines a sodium target per litre with your bottle size and label sodium to suggest scoops per bottle.
1. Estimate a sodium target per litre
First, the tool estimates a sodium target per litre for your drink using your body weight and sweat level. Lighter sweaters get a lower band, medium sweaters a mid-range band, and salty/heavy sweaters a higher one, all within typical sports drink ranges used for longer training.
2. Convert your bottle size into litres
Your bottle size is converted into litres:
Litres = Bottle volume ÷ 1000 (mL) in metric mode, or an equivalent conversion from fluid ounces in US mode.
This lets the calculator work in per-litre terms and then scale down to one bottle.
3. Work out target sodium per bottle
The sodium target per litre is multiplied by your bottle volume in litres:
Target sodium per bottle = Target mg/L × Bottle litres
That gives a single number in milligrams for one bottle that matches the chosen range.
4. Convert label sodium into scoops per bottle
Your drink mix label tells you mg of sodium per scoop. The tool divides the target mg per bottle by that label number, then rounds to a simple scoop amount:
Scoops per bottle ≈ Target mg per bottle ÷ mg per scoop
The result is rounded to quarter scoops and capped within a reasonable range so the suggestion stays practical.
5. Compare the actual mix with the target
Finally, the calculator works out how much sodium your bottle would really contain at that scoop level and compares it with the target band. It labels the result as below, around or above the target to keep the output easy to read.
Remember that health, medications and environment all change what makes sense for you. This page is a planning helper for healthy adults in training, not a tool for treating dehydration, illness or electrolyte disorders.
References and further reading on sports hydration and electrolytes
These resources discuss sports drinks, sodium in exercise and fluid replacement more broadly:
- American College of Sports Medicine — Exercise and fluid replacement (position stand) — describes fluid and sodium replacement during prolonged exercise, including example sodium ranges per litre in sports drinks.
- German Journal of Sports Medicine — Fluid replacement in sports (position paper) — reviews sports drink composition and suggests that many sports drinks include sodium in a band that can help replace some sweat losses during longer activity.
- British Nutrition Foundation — Hydration — explains when sports drinks with electrolytes may be useful and when water is enough for most people.
Use these as general background and pair them with specific advice from your own healthcare or sports medicine team, especially if you have heart, kidney or blood pressure conditions or use medications that affect fluid balance.