Welcome to the Half Marathon Calorie Calculator! This tool helps you estimate how many calories you burn while running a half marathon. Whether you’re training for your first 21.1 km race or looking to track energy expenditure for performance and nutrition planning, this calculator provides quick and reliable estimates. By entering your body weight and race details, you can get a personalized calorie burn figure. Start using the calculator right away, or keep reading to understand the formulas, examples, and parameters behind the calculations.
Understanding the Formula
The Half Marathon Calorie Calculator uses three different methods to estimate calorie burn, ranging from simple to highly detailed.
1. Basic Calculation (Quick Estimate)
Formula:
Calories Burned = (Your Body Weight in lbs / 150) × 1500
- This method assumes an average burn of about 1500 calories for a 150 lb runner.
- It’s fast and easy but less precise.
2. General Running Formula (More Accurate)
Formula:
Calories Burned = Your Body Weight in kg × Distance in km
- For a half marathon, the distance is always 21.0975 km.
- Your body weight is converted from pounds to kilograms (divide by 2.20462).
- This gives a more tailored calorie estimate.
3. METs Formula (Most Detailed)
Formula:
Calories Burned = (METs × 3.5 × Your Body Weight in kg) / 200 × Duration in minutes
- METs (Metabolic Equivalent of Task) for running a half marathon is usually 13.3.
- This method also includes your finishing time, giving the most accurate result.
These three approaches let you choose between a quick estimate or a detailed calculation depending on your needs.
Parameters Explained
Here are the main inputs you’ll encounter in the calculator:
- Your Body Weight in lbs or kg: A key factor since heavier runners burn more calories.
- Distance in km: Fixed at 21.0975 km for a half marathon.
- Duration in minutes: How long it takes you to complete the race. Faster times generally mean higher intensity.
- METs value: A standardized measure of exercise intensity. Running a half marathon corresponds to about 13.3 METs.
Each parameter ensures the results are tailored to your fitness profile and race performance.
How to Use the Half Marathon Calorie Calculator — Step-by-Step Example
Let’s try an example using the General Running Formula:
- Runner’s weight = 160 lbs
- Convert weight to kg: 160 / 2.20462 ≈ 72.6 kg
- Distance = 21.0975 km
Calories Burned = 72.6 × 21.0975 ≈ 1532 calories
If the same runner completed the half marathon in 120 minutes (2 hours), using the METs formula:
Calories Burned = (13.3 × 3.5 × 72.6) / 200 × 120
= (3383.37 / 200) × 120
= 16.92 × 120
= 2030 calories
Final Result: Depending on the method, this runner burns between 1530–2030 calories in the half marathon.
Additional Information
Here’s a quick reference table for estimated calories burned in a half marathon at different body weights (using the General Running Formula):
| Body Weight (lbs) | Body Weight (kg) | Calories Burned (Approx.) |
|---|---|---|
| 120 lbs | 54.4 kg | 1148 calories |
| 150 lbs | 68.0 kg | 1435 calories |
| 180 lbs | 81.6 kg | 1723 calories |
| 200 lbs | 90.7 kg | 1914 calories |
This table helps you estimate energy expenditure without doing manual calculations.
FAQs
On average, most runners burn between 1200–2000 calories, depending on weight, speed, and duration.
The METs formula is the most precise since it factors in both weight and race duration.
Yes, faster running increases intensity (higher METs), leading to greater calorie burn per minute.