How this calculator works
A sports drink concentration is stated as grams of carbohydrate per 100 millilitres, written as a percentage. A six percent solution therefore has six grams of carbohydrate in every 100 millilitres, or 60 grams per litre. The sugar mass follows directly from the bottle volume and the chosen concentration, and each gram of carbohydrate provides about four kilocalories. Sodium is added as salt: sodium makes up about 39.3 percent of sodium chloride by mass, so one milligram of sodium needs about 2.54 milligrams of salt. The page converts the sodium target per litre into salt grams for the bottle, then into teaspoons for a kitchen measure.
Formula
Carbohydrate grams = bottle volume in millilitres x concentration as a fraction. Energy = carbohydrate grams x 4. Sugar teaspoons = carbohydrate grams / 4.2. Sodium milligrams = sodium per litre x bottle volume in litres. Salt grams = sodium milligrams / 1000 x 2.542. Salt teaspoons = salt grams / 5.69.
Worked example
A 750 mL bottle at six percent needs 750 x 0.06 = 45 g of carbohydrate, which is 180 kcal. At 4.2 g per teaspoon that is 10.7 teaspoons of table sugar. If the target is 500 mg of sodium per litre, the bottle needs 0.75 x 500 = 375 mg of sodium, which is 0.375 x 2.542 = 0.95 g of salt, or about 0.17 teaspoons.
Advertisement
Frequently asked questions
What concentration should I use?
Most commercial sports drinks sit between four and eight percent. Above about eight percent the drink empties from the stomach more slowly and can cause stomach upset during hard exercise. For long, hot sessions, a six percent drink is a common middle ground.
Can I use table sugar instead of maltodextrin?
Yes. Table sugar is a mix of glucose and fructose, which is the combination many sports drinks use. Maltodextrin can reach a higher concentration with less sweetness, but it is not necessary for a basic homemade drink.
How much sodium do I need?
Sweat sodium varies widely between people, from a few hundred to over 1,500 mg per litre. A drink around 300 to 700 mg per litre suits many athletes. Salty sweaters should use the higher end and may also add salt to food.
Is a homemade drink as safe as a commercial one?
The ingredients are ordinary food, but hygiene matters. Use clean bottles, mix with potable water and refrigerate. Discard anything that has been left warm for hours, and do not use the drink as a substitute for medical advice if you have a kidney or heart condition.