Ultra Marathon Nutrition Calculator

Plan calories, electrolytes, and fluid intake per hour for ultra marathon distances. Get personalized nutrition targets based on weight, pace, and conditions.

Inputs

Race Distance

miles

Body Weight

lbs

Expected Pace Minutes

Expected Pace Seconds

Expected Temperature

°F

Effort Level

Tab to move between fields

Results

Target Calories/Hour

234 cal

≈ 2 apples

Carbs per Hour58 g

Fluid per Hour20 oz

Sodium per Hour400 mg

Potassium per Hour150 mg

Estimated Finish Time10h 0m

Total Calories Burned5,840 cal

Total Calories to Consume2,336 cal

Total Fluid Needed6 L

Total Sodium Needed4,000 mg

Total Caffeine Target290 mg

Aid Station Stops9

Calories per Stop260 cal

How to Use This Calculator

Enter your Race Distance in miles, Body Weight in pounds, and Expected Pace.
Set the Expected Temperature and your Effort Level (easy, moderate, or hard).
Review target Calories per Hour, Carbs per Hour, Fluid per Hour, and Sodium per Hour.
Check the Estimated Finish Time and Total Calories Burned for full-race planning.
Use these targets to build your aid station nutrition strategy and drop bag contents.

How the result changes with Expected Pace Minutes

Expected Pace Minutes	Target Calories/Hour
8.8	319 cal
13	216 cal
19	148 cal
23	122 cal

What each input means

Race Distance: Total race distance in miles. Common ultras: 50K (31.1), 50 miles, 100K (62.1), 100 miles.
Body Weight: Your body weight in pounds. Heavier runners burn more calories and need more fluids per hour.
Expected Pace Minutes: Minutes portion of your expected average pace per mile including walking. Ultras are typically 10-16 min/mile.
Expected Pace Seconds: Seconds portion of your expected pace per mile.
Expected Temperature: Expected average temperature during the race. Higher temps significantly increase fluid and electrolyte needs.
Effort Level: Your expected effort level. Higher intensity increases calorie burn and electrolyte loss.

How this is calculated

Worked example, using the default values

Identify Input Parameters
4 parameters
Race Distance = 50, Body Weight = 160, Expected Pace Minutes = 12, Expected Pace Seconds = 0 = 6 input(s) provided
Calculate Target Calories/Hour
Target Calories/Hour
234 = 234
Calculate Carbs per Hour
Carbs per Hour
58 = 58
Calculate Fluid per Hour
Fluid per Hour
20 = 20

Engine last updated August 5, 2026. Checked against 1 independently-derived test — how we verify calculators.

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