Sports Drink Calculator Formula

Understand the math behind the sports drink calculator. Each variable explained with a worked example.

Use the Sports Drink Calculator

Formulas Used

Sugar/Carb Powder

sugar_g = round(water_ml * carb_pct / 100 * intensity)

Salt (sodium)

salt_g = round(water_ml * 0.001 * intensity * 10) / 10

Total Fluid Needed

total_fluid_ml = round(water_ml * duration_hr)

Bottles (750 mL)

bottles = ceil(water_ml * duration_hr / 750)

Variables

VariableDescriptionDefault
water_mlWater Volume(mL)750
intensityActivity Intensity1
duration_hrActivity Duration(hr)1.5
carb_pctDerived value= 4 + intensity * 2calculated

How It Works

How to Mix a Sports Drink

Carbohydrate Concentration

Sports drinks should be 4-8% carbohydrate for optimal absorption:

  • Light activity: 4-5% (lower end)
  • Moderate activity: 5-6%
  • Intense activity: 6-8%

    • Concentrations above 8% slow gastric emptying and can cause stomach issues.

    Sodium

    Add 0.5-1.0 g of sodium per liter of water. This replaces sweat losses and improves fluid absorption. Heavy sweaters may need more.

    Mixing

    Dissolve sugar and salt in warm water, then add cold water and ice. Taste should be mildly sweet, not overpowering.

    Worked Example

    Mix a sports drink for a 1.5-hour moderate run using 750 mL of water.

    water_ml = 750intensity = 1duration_hr = 1.5
    1. 01Carb percentage = 4 + 1 x 2 = 6%.
    2. 02Sugar = 750 x 6/100 x 1 = 45 g (about 3 tablespoons).
    3. 03Salt = 750 x 0.001 x 1 = 0.8 g (about 1/8 tsp).
    4. 04Total fluid needed = 750 x 1.5 = 1125 mL.
    5. 05Bottles = ceil(1125 / 750) = 2 bottles.

    Ready to run the numbers?

    Open Sports Drink Calculator